Abstract: Ni₅₀Mn₃₅In_15-xSi_x alloy samples were prepared by melt quenching method, and the magnetic properties were measured by using PPMS, then the magnetocaloric effect and crystal structure of the samples were analyzed. The results show that with the increase of Si doping Ni₅₀Mn₃₅In_15-xSi_x, Heusler alloy has an impact on the internal magnetic moment of the alloy,the magnetization at low temperature changes, （T_c）^1/2 gradually decreases. The magnetic phase change at （T_c）^1/2 causes a large change of magnetic entropy, and the wide temperature range of the phase change makes it possible to obtain a high refrigerant capacity. Under the applied magnetic field of 5 T, when x=0.8, at 316.6 K, the maximum refrigerant capacity reaches 187.92 J/kg at this time,and the magnetic entropy change is 5.63 J/kg.