This paper systematically reviews the development drivers and prospects of day medicine in China. By analyzing policy evolution, practical outcomes, and international comparisons, it elaborates on the inevitable expansion of day medicine from day surgery to multidisciplinary services. It further highlights the significant role of its advantages of high quality, efficiency, and low cost in alleviating high-quality medical resource shortages and improving service effectiveness. Against the backdrop of ongoing healthcare payment reforms and hospital operational innovations, the paper also explores future trends in disease-type expansion, institutional coordination, and intelligent support for day medicine, aiming to provide references for further optimization of China’s day medicine system.