NOVELTY - Preparation of coal-based natural gas involves gasifying coal, passing obtained purified gas to heat exchanger, desulfurizing heat-exchanged gas, deoxidizing desulfurized gas to obtain synthesis gas, separating methanol from circulating gas, passing into heat exchanger, sending mixture of deoxidized synthesis gas and heat-exchanged circulating gas to methanol synthesis tower to produce methanol, passing crude methanol into methanol rectification tower, washing obtained methanol purge gas and passing obtained product to methanation reaction system to generate natural gas.    USE - Preparation of coal-based natural gas (claimed).    DETAILED DESCRIPTION - Preparation of coal-based natural gas with peak regulation through methyl alcohol synthesis involves gasifying coal to obtain purified gas, passing purified gas to heat exchanger through a compressor in compression circulation section, passing heat-exchanged purified gas into desulfurization reactor for desulfurization, such that desulfurized gas containing sulfur content of 10-100 ppb, passing desulfurized gas into deoxidation reactor for deoxidation, such that oxygen content becomes 500-1200 ppm to obtain synthesis gas, separating methanol from circulating gas using compressor in compression circulation section, passing into heat exchanger, directly sending mixture of deoxidized synthesis gas and heat-exchanged circulating gas mixed in synthetic system to methanation reaction to generate coal gas or sending mixture of deoxidized synthesis gas and heat-exchanged circulating gas to methanol synthesis tower to produce methanol, filling mixed gas of synthesis gas and circulating gas in reaction tube filled with catalysis synthesis reaction mixture, sending obtained reaction mixture into methanol separator, obtaining liquid phase, at same time, passing one portion of generated gas as methanol purge gas into water-washing tower and sending other portion of obtained gas as recycle gas into synthetic system through compressed circulation section, washing obtained liquid phase in washing tower using methanol washing solution, passing washed product into flash tank, flash vaporizing to generate crude methanol, passing crude methanol into methanol rectification tower to produce purified methanol which is methanol product or separating methanol purge gas from crude methanol, washing methanol purge gas in washing tower using water, such that methanol concentration is reduced to 100-300 ppm, and passing obtained product to methanation reaction system to generate natural gas.