The invention provides a bottom boundary layer in-situ 
observation system suitable for a shallow water viscous 
seabed and an arrangement method thereof. A hydraulic 
pile foundation 
system which is easy to manufacture, low in cost and easy to operate is established, the piling depth can be guaranteed, the anti-
sedimentation and stability functions of the 
seabed observation system are achieved, andpiling of the designated number and positions can be conducted according to needs when the 
observation system is arranged; a stainless steel 
pipe free 
assembly means is adopted, an instrument arrangement area and a turbulence-free observation area are built, integration of various instruments is achieved, turbulence influences of an instrument frame body on an observation space are avoided, and the instrument arrangement area can be adjusted and matched according to user requirements; the observation frame supporting legs and the top ends of the bottom piles are systematically fixed through the foot plates, limitation of the weight of an observation 
system is avoided, and the defects of a settlement plate are overcome. All the components are convenient to replace or maintain, the cost is low, the bottom boundary layer in-situ observation 
system can be widely applied, and the problems of full-layer, multi-parameter, continuous, stable, high-cost and the like of bottom boundary layer in-situ observation are effectively solved.