The invention relates to a large-angle fin angle conveying mechanism which converts linear displacement into angular displacement. The fixing mechanism of the fin angle conveying mechanism is articulated with the conveying mechanism of the fin angle conveying mechanism through a pin shaft. The conveying mechanism of the fin angle conveying mechanism is connected with the fin angle transmitter through a guide rod, and the fixing mechanism of the fin angle conveying mechanism is connected with the piston rod of the rotating fin cylinder through a connecting rod. A piston rod of a rotating fin cylinder drives a fixing mechanism of a fin angle conveying mechanism to move up and down through a connecting rod, so as to drive the guide sleeve cylinder block of the conveying mechanism of the fin angle conveying mechanism to rotate, the guide rod in the guide sleeve cylinder block is rigidly connected with the potentiometer of the fin angle transmitter, and the fin angle of the fin angle transmitter is changed through the guide rod along the movement length of the guide sleeve cylinder block, and the linear displacement of the fin angle transmitter cylinder is converted into the angular displacement. A ball guide sleeve is introduced to convert the linear displacement of the rotary fin oil cylinder into an angular position, and the transmission angle is determined by the length of the ball guide sleeve and the guide rod, so that the linear displacement of the rotary fin oil cylinder of the actuator is converted into an angular displacement.