The g-C3N4/Bi2MoO6 precursor was prepared by solvothermal method with melamine, sodium molybdate dihydrate and bismuth nitrate pentahydrate as raw materials, then loaded Ag3PO4 nanoparticles by coprecipitation method, the g-C3N4/Bi2MoO6/Ag3PO4 composite was obtained. The composite was characterized by XRD, FTIR, XPS, SEM and UV-Vis DRS. Tetracycline hydrochloride (TC) was used as the target degradation, the results showed that the degradation rate of 10 mg/L TC reached 93% in 50 min under visible light irradiation. The corresponding rate constant was 0.033 min-1, which was higher than g-C3N4, Bi2MoO6 and Ag3PO4 with 33 times, 3.6 times and 1.5 times, respectively, showing that the g-C3N4/Bi2MoO6/Ag3PO4 composite had the best catalytic performance among all the catalyst. After four cycles with g-C3N4/Bi2MoO6/Ag3PO4, the degradation rate of TC was 71%, higher than Ag3PO4, indicating that the g-C3N4/Bi2MoO6/Ag3PO4 composite had better stability. According to the experimental results of free radical capture, the main active species in the process of TC degradation were ·OH- and ·O2–. Finally, the possible degradation mechanism and degradation path were supposed.