The lithium vanadium phosphate (Li3V2(PO4)3 solid cathode materials were synthesized by microwave-heated sol-gel method using lithium hydroxide, ammonium metavanadate, phosphate and citric acid as starting materials. The test was conducted with orthogonal experiment method. The optimal conditions for (Li3V2(PO4)3 synthesis were determined to be microwave heating time of 10 min, microwave power of 700 W, Li/V molar ratio of 3.05:2.0 and pH value(gel solution) of 7.0. The synthesized (Li3V2(PO4)3 under the optimal conditions demonstrated perfect crystal growth and good electrochemical performance with initial charge/discharge specific capacity of 172.42 mAh·g-1/154.93 mAh·g-1 and discharge decay rate of 2.25 % after 50 cycles. The lithium ion diffusion coefficient was determined to be 1.434 ×10-8 cm2·s-1 by electrochemical impedance spectroscopy and mathematical models derived from simulative equivalent circuit.