To investigate the effects of the potato-legume intercropping system on soil enzyme activity and potato yield in the arid region of southern Ningxia, a field positioning experiment with three different planting patterns, including potato monoculture (P), potato-soybean intercropping (PS), potato-broad bean intercropping (PB) were conducted for two consecutive years from 2020 to 2021 to explore the differences of soil enzyme activity and potato yield in different intercropping patterns. The results revealed that intercropping significantly enhanced the activities of catalase, urease, sucrase and acid phosphatase in 0-60 cm soil. The enzyme activities of each treatment were basically manifested as PS>PB>P, which increased first and then decreased during the whole growth period, and gradually decreased with the deepening of soil layer. In 2020, the activities of catalase, urease, sucrase and acid phosphatase of PS were 0.51%-4.69%, 7.96%-152.23%, 3.22%-192.00%, 5.75%-175.80% and 1.28%-9.10%, 4.11%-53.99%, 3.61%-140.27%, 4.27%-133.7% higher than those of PB and P, respectively. In 2021, the activities of catalase, urease, sucrase and acid phosphatase of PS were 0.20%-4.63%, 0.84%-93.93%, 4.26%-143.26%, 4.85%-50.41% and 0.13%-8.83%, 0.05%-94.53%, 1.13%-334.33%, 7.15%-99.34% higher than those of PB and P, respectively. The potato yield showed PS>PB>P in both years. In 2020, PS and PB significantly increased by 13.96% and 5.33% compared with P, respectively. In 2021, PS and PB significantly increased by 33.85% and 14.31% compared with P, respectively (P<0.05). Through principal component analysis, the comprehensive scores of P, PS and PB in 2020 and 2021 were -0.79, 2.55, -1.75 and -2.69, 3.36, -0.68, respectively, and PS was the highest in both years. The intercropping of potato and leguminous crops promoted the increase of soil catalase, urease, sucrase and acid phosphatase activities, which provided a certain basis for soil formation and soil fertility improvement, and provided a better environment for potato growth and development, thus increasing the yield of potato. In this study, potato-soybean intercropping had the advantage of intercropping and could significantly increase potato yield.