In order to evaluate the propulsive efficiency of turbofan, turboprop and prop-fan engines, a mathematical model for propulsive efficiency analysis was established by using energy-momentum method based on the model of separate exhaust turbofan engines, and a unified propulsive efficiency analysis method was formed for turbofan, turbofan and propeller fan engines. Different external fan pressure ratio, equivalent bypass ratios and different flight Mach number are selected for calculation. The calculation results show that the propulsion efficiency of turboprop engine is higher at medium to low flight Mach number, the propulsion efficiency of prop-fan engine is higher at medium to high flight Mach number, and the propulsion efficiency of turbofan engine is higher at high subsonic flight Mach number. The results confirm the existing flight Mach number interval distribution law of the superior propulsion efficiency of turboprop, prop-fan and turbofan engines, and provide a method for the research and analysis of the propulsion efficiency of turbofan, turboprop and prop-fan engines.