A pulsation-free wet spraying machine resolves the issue of pulsing during pumping of a concrete spraying machine The wet spraying machine includes a frame, a pumping mechanism, a swing mechanism and a hydraulic system, wherein the pumping mechanism includes a hopper, a material chamber, a concrete feeding mechanism, an auxiliary feeding mechanism and a distribution valve. The hopper of the pumping mechanism is disposed above the material chamber. The distribution valve is disposed inside the material chamber, the concrete feeding mechanism and the auxiliary feeding mechanism both include a hydraulic cylinder, a concrete piston and a concrete cylinder, a discharge pipe is a three-way pipe fixed at a side surface of the material chamber, an auxiliary discharge pipe of the discharge pipe is connected with an auxiliary concrete cylinder, and a through hole is disposed on the auxiliary concrete cylinder. The swing mechanism includes a swing hydraulic cylinder, a swing arm and a swing hydraulic cylinder base, an auxiliary piston rod of the auxiliary feeding mechanism passes through a mandrel to push an auxiliary concrete piston to move inside the auxiliary concrete cylinder. In addition, the pulsation-free wet spraying machine stably feeds a material, has a compact structure, and is wear-resistant.