The invention discloses a stack-structured radio frequency power amplifier based on positive feedback. The stack-structured radio frequency power amplifier comprises an input matching circuit, an output broadband matching circuit, a bias circuit A, a bias circuit B and a power amplifying circuit which is formed by stacking drain electrodes and source electrodes of at least two transistors, a signal source is connected with a grid electrode of the transistor on the bottommost layer of the power amplifying circuit through the input matching circuit, the bias circuit B is connected with the grid electrode as well, the bias circuit A is connected with grid electrodes of other transistors of the power amplifying circuit, a feedback capacitor is connected between the grid electrodes and the source electrodes of other transistors, and the drain electrode of the transistor on the uppermost layer is connected with a load through the output broadband matching circuit. By the circuit structure, linearity and voltage resistance of the stack-structured radio frequency power amplifier are improved, output voltage swing, working bandwidth, power efficiency, power gain and maximum output power of the radio frequency power amplifier can be improved, and the stack-structured radio frequency power amplifier has good secondary harmonic suppression effect.