Chemotherapy has been clinically used for cancer treatment. However, insufficient drug concentration at the target site limits the therapeutic effect. Here, we introduce an in vivo target drug enrichment method, which is based on spatiotemporal acoustic node modulation (STANM). In such a time-varying acoustic field, there are spatially-shifting acoustic radiation forces on the drug-loaded microparticles that move them toward the focus. Based on this mechanism, the enhanced enrichment by STANM showed an approximately 200-fold microparticle concentration increase compared with the control group of no acoustic enrichment. The in vivo test in mice bladders verifies that the target drug enrichment based on STANM decreased tumor weight by 72.43% compared to traditional chemotherapy. The proposed target drug enrichment method paves the way for enhanced cancer therapy.