The invention provides a parallel-air inlet type rear duct ejector in a variable cycle engine adjustable mechanism. The parallel-air inlet type rear duct ejector comprises an actuator cylinder, a link arm, a rotating shaft, a sleeve, a bearing, a bearing pedestal, an elastic collar, a connecting rod, an inner engine case, an outer engine case, a valve body, a sliding strip, a friction block and a friction block installation platform. According to the parallel-air inlet type rear duct ejector in the variable cycle engine adjustable mechanism, the actuator cylinder is used for carrying out driving, so that the outlet area of an engine outer duct is continuously adjustable, the structure is simple, the number of parts is small, the weight is low, and the parallel-air inlet type rear duct ejector is higher in stability and reliability compared with the design scheme of an existing variable cycle engine rear duct ejector.