According to the requirements of the marine instrument testing field construction, it is necessary to design and analyze the standpipe and its subsidiary structure which is applied for the marine instruments measurement like sensors. The equipment is composed of different diameter PE pipes,which is nested as the main body and can be used to test 5 sensors within diameter 50 mm.Sensor holding device can automatically adapt to the sea tide variation, and the propeller rotation can form a vortex to brush the biofouling organisms to slow down the adhesion. Through CFD simulation analysis of the flow around the cylinder and the failure analysis of the fixed clamp and bolt set, the results show the wave guiding tube can guide the flow around the cylinder. It can control the flow direction of the tail flow and weaken the influence of the vortex when the fluid flows through the standpipe, and the equipment has the better effect of wave resistance and reliability on the sea. Practical test operated at the Hydrometric Station of water testing station in Luchaogang of Pudong New District, Shanghai,shows that the overall structure, strength and deformation of the device meet the design standards and can satisfy the requirements of the measuring equipment in the marine instrument testing field.