In order to solve the problem of image enhancement in quantum image processing, a quantum image pseudo color coding method based on gray level-color transformation method is proposed. Based on the generalized quantum image representation(GQIR) model, the hot metal code segment function is quantized, and the quantum circuit diagram of the algorithm is given. The quantum circuit design is divided into three parts: quantum R converter, quantum G converter and quantum B converter, and the number of basic quantum gates used in the total quantum circuit diagram is 2947. Compared with classical pseudo color coding, quantum image pseudo color coding is based on the superposition and coherence of quantum states, which can reduce the spatial and temporal complexity exponentially. The simulation results show that the algorithm is feasible.