The invention relates to the technical field of human blood detection. A flow cytometry detection fluid circuit system comprises a diluent injection system, a hemolysin and blood sample injection system and a pressure system, wherein for the diluent injection system, a diluent injector is driven by a motor, and the diluent injection system is connected with a diluent barrel to suck a diluent to inject to a flowing chamber, a reaction tank and a sampling needle cleaning device; for the hemolysin and blood sample injection system, a hemolytic agent injector is driven by a motor, the hemolysin and blood sample injection system is used for sucking the hemolytic agent to inject to the reaction tank, and the sample injection sucking collects a distribution blood sample to inject to the reaction tank; for the pressure system, a diaphragm pump is connected with a pressure chamber to form positive and negative pressures, the pressure system is used for pumping waste liquid of the sampling needle cleaning device, sucking a sample in the reaction tank to a sample injection port of the flowing chamber, carrying out gas blowing stirring and evacuation on the reaction tank, and pumping the diluent to the reaction tank. According to the invention, the number of reaction tanks is reduced, system structure and complexity are simplified, and miniaturization and low cost are realized for machines.