In order to alleviate the shortage of natural river sand resources and reduce the cost and energy consumption of UHPC, high-value utilization of manufactured sand was carried out. Based on the compact packing theory, UHPC with high content of manufactured sand was designed. The effects of different substitution of manufactured sand on the working ability, mechanical property, microstructure, cost and carbon emission were studied. The results indicated that the incorporation of manufactured sand negatively affected the workability of UHPC. The compressive strength of UHPC increased and then decreased with the increase of MS substitution. At 70 % replacement of manufactured sand, the slump flow of UHPC was 655 mm, and it still maintains excellent workability. The 7 d and 28 d compressive strengths were increased by 5.3 % and 8.8 %, respectively, compared with the control specimens. At this time, the tensile strength reached 8.99 MPa and the ultimate tensile strain was 0.78 × 10−3. The microstructure showed that MS could refine the UHPC pore structure and reduce the porosity at 70 % substitution. The results demonstrated that 70 % substitution of manufactured sand instead of quartz sand can not only improve the mechanical properties of UHPC, but also reduce the cost and CO2 emission. Each cubic meter of UHPC can save the 380 CNY and reduce CO2 emission by 14.2 kg, with good economic benefits. The study aims to provide technical support for the high-value utilization of manufactured sand in UHPC.