NOVELTY - A lithium iron phosphate and carbon nano-tube composite material preparation method involves weighing (in vol.%) ferrous source (5-10), phosphoric acid (5-10), lithium source (15-30), reducing agent (10-15), surface active agent (20-30) and carbon nano-tube (20-30) and adding lithium source and phosphate source in a container, followed by mixing with mixed solvent to obtain solution. The obtained container is placed in ultrasonic cleaner for ultrasonic dispersing and dissolving, followed by stirring and adding ferrous source and reducing agent. The obtained solution is subjected to dispersing.    USE - Method for preparing lithium iron phosphate and carbon nano-tube composite material for a lithium ion battery.    ADVANTAGE - The method enables preparing composite material with high purity, small grain diameter and excellent electrochemical performance in an effective manner.    DETAILED DESCRIPTION - A lithium iron phosphate and carbon nano-tube composite material preparation method involves weighing (in vol.%) ferrous source (5-10), phosphoric acid (5-10), lithium source (15-30), reducing agent (10-15), surface active agent (20-30) and carbon nano-tube (20-30) and adding lithium source and phosphate source in a container, followed by mixing with mixed solvent to get solution (5 mol/l). The obtained container is placed in ultrasonic cleaner for ultrasonic dispersing and dissolving, followed by stirring and adding ferrous source and reducing agent. The obtained solution is subjected to dispersing and dissolving to obtain mixed solution (5 mol/l), followed by adding surfactant with mixed solution and subjecting mixed solution to perform ultrasonic dispersion. The obtained solution is added with carbon nano-tube, followed by ultrasonic dispersing, dissolving and mixing to get solution. The obtained solution is put in a PTFE reaction kettle and reacted at 16-20 degrees C for 6 hours, followed by cooling to room temperature and vacuum filtering. The obtained filtrate is washed by de-ionized water and filtered by filter paper in funnel to obtain black powder, followed by putting the black powder in a drum wind drying box at 40 degrees C to obtain lithium iron phosphate/carbon nano-tube precursor that is added with sucrose (25-45%). The obtained mixture is put in a tubular furnace at 60-80 degrees C for 6-10 hours to obtain the lithium iron phosphate/carbon nano-tube composite material.