According to the phase change property of carbon dioxide and the rapid cooling ability of liquid nitrogen, an experimental system of quick-frozen strawberry by combined jet of carbon dioxide and liquid nitrogen was designed. Through a series of experiments, the pressure changes and jet outlet temperature at different nitrogen jet speeds at different temperatures were studied. Then, the effects of nitrogen injection speed at different low temperatures and different inlet positions in the quick-frozen room on the quick-frozen strawberry freezing rate was investigated. The final results show that when the jet speed of low-temperature nitrogen increases, the pressure loss in the flow process also increases gradually. At the same time, the speed of mixing will increase, and the disturbance will increase, and the outlet jet temperature will also decrease. When the nitrogen inlet speed was 0.2 m/s, the temperature between the strawberry was uniform. Different inlet and outlet positions had no influence on the freezing time of strawberry. Quick-freezing room (c) improves the heat transfer efficiency and makes the temperature of strawberries more uniform. The results obtained lay a foundation for further research and development of an efficient quick-frozen product device.