NOVELTY - Preparing biologic diesel oil directly from raw material by coupling method of supercritical fluid extraction and trans-esterification comprises entering higher pressure carbon dioxide (CO2) from CO2 storage tank (2) into a dry-filter (5); transmitting fluidified CO2 by plunger pump (4), mixing from lower carbon alcohol storage tank (3), pressurized by higher pressure metering pump (7); pre-heating, extracting; controlling flow speed; transmitting product, separating CO2 and liquid component; transmitting CO2 gas into a storage tank (16); separating and purifying, heating and boiling.    USE - The process is useful for preparing biologic diesel oil directly from raw material by coupling method of supercritical fluid extraction and transesterification (claimed).    ADVANTAGE - The process can prepare biologic diesel oil using one step method under soft condition, the technology is simple, and the cost is low.    DETAILED DESCRIPTION - Preparing biologic diesel oil directly from raw material by coupling method of supercritical fluid extraction and trans-esterification comprises entering higher pressure carbon dioxide (CO2) from a CO2 storage tank (2) into a dry-filter (5) by way of a pressure reducing valve, carrying through a primary condensation using a condenser (7); transmitting the further fluidified CO2 into a mixer (19) by a plunger pump (4), mixing it with alcohol solution from lower carbon alcohol storage tank (3) and pressurized by a higher pressure metering pump (7); pre-heating the mixed medium by using a pre-heater (9), then transmitting into a supercritical fluid extraction machine (10) by using an adjusting valve (13), extracting with material which is contained into supercritical fluid extraction machine (10) before; controlling the flow speed of the fluid in the extraction machine (10) by using the adjusting valve (13), for making it contact and react with the material fully, then transmitting the extraction liquid into a fixed bed higher pressure reactor (11) contained with catalyst, supplying the reaction low carbon alcohol by the side way of stream (b) according to mol ratio of oil and alcohol of 3:1-40:1, controlling the flow speed of the fluid in the reactor (11) by using the adjusting valve (13), for making it contact and react with the catalyst fully; transmitting the product of the reaction into a separator (12), separating CO2 and liquid component; transmitting CO2 gas into a storage tank (16) after weighting it by using a flow meter (15) by the stream (e) for reclaiming, or discharging it directly by the stream (m); transmitting the liquid product at the bottom of the separator (12) to a vacuum rectifying tower (18) by the stream (h), vacuum rectifying the alcohol which is not react, condensing and reclaiming the alcohol distilled from the top of the tower by using the condenser (17), transmitting to the lower carbon alcohol storage tank (3) for cycling and using; and the negative pressure at the top of the vacuum rectifying tower (18) is offered by a cavity system (24), transmitting the biologic diesel oil and glycerin at the bottom of the tower to a biologic diesel oil refining system (25), for separating and purifying, heating and boiling the product at the bottom of the tower by using a re-boiler (23).    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic diagram for preparing biologic diesel oil directly from raw material by coupling method of supercritical fluid extraction and transesterification.    CO2 storage tank; (2)    Lower carbon alcohol storage tank; (3)    Plunger pump; (4)    Dry-filter; and (5)    Condenser (7)