The invention discloses a handheld paint spraying machine. The handheld paint spraying machine comprises a support, wherein a booster pump is fixedly mounted on the support, a liquid inlet valve, a discharge valve and a pressure adjusting valve are arranged on the booster pump, the liquid inlet valve is connected with a liquid suction pipe, and the discharge valve is connected with a spray gun through a paint spraying pipe; a liquid discharging pipe is arranged at the lower part of the booster pump; a baffle is arranged below the booster pump; a handle is arranged on the support; a filtering ball is arranged at the head of the liquid suction pipe; rollers are arranged at the lower part of the support; a manual auxiliary valve is arranged at the bottom of the booster pump; the handheld paint spraying machine further comprises a paint purifying device, and the head part of the liquid suction pipe extends into a discharging hole of the paint purifying device. The handheld paint spraying machine has the advantages that the spraying quality and efficiency are high, the spraying effect is good, the coating is uniform, the spraying range is long, the handheld paint spraying machine is convenient to carry and move, the utilization rate of paint is high, and the costs are reduced.