The invention relates to an ocean seedling cultivation machine and provides a seaweed seedling cultivation seedling washing machine so as to solve the technical problems that seedling bed washing is large in labor intensity and low in efficiency in the process of current seaweed seedling cultivation. The seaweed seedling cultivation seedling washing machine comprises a base and a support fixed on the base and is characterized in that the position close to the top of the support is hinged with a swing rod through an articulated part, the tail end of the swing rod is connected with a spraying pipe, the spraying pipe is parallel to the support along the transverse direction and connected with the swing rod in a perpendicular mode, the spraying pipe is connected with a water supply device, an articulated shaft is hinged in the middle of the swing rod, the top end of a crank is hinged with the swing rod through the articulated shaft, the other end of the crank is connected with a rotating plate on a machine frame in an eccentric mode, and the rotating plate is driven by a motor on the machine frame. The seaweed seedling cultivation seedling washing machine is simple in structure, low in manufacture cost, simple and convenient to operate, safe, and capable of effectively lightening labor intensity, reduces the number of operating personnel, and improves seedling bed washing efficiency.