The invention relates to a small-sized semiautomatic kelp dragging harvesting boat. The small-sized semiautomatic kelp dragging harvesting boat comprises a boat body and is characterized in that a hoisting component is vertically fixedly arranged on the boat body; the hoisting component comprises a standing column, and a standing column motor component is fixedly arranged at the top of the standing column; the standing column motor component comprises a standing column motor which drives an upper crossbeam component to horizontally rotate around the standing column through a sprocket transmission mechanism; an upper crossbeam movement motor component is fixedly arranged on the upper crossbeam component and comprises an upper crossbeam movement motor and a rope sheave component, and the crossbeam movement motor drives the rope sheave component to rotate through a worm and gear mechanism to wind and unwind a hoisting rope; the lower end of the hoisting rope is connected with a mechanicalarm component; the mechanical arm component comprises a pneumatic slider, and a pin I penetrates a pair of clamping jaws and is fixed to an air cylinder cover; a pair of pins II is inserted into theslide grooves of corresponding clamping jaws and fixed to pneumatic sliders, and the pneumatic sliders move vertically to push to bottoms of the clamping jaws so as to drive the pair of clamping jawsto rotate around the pin I to achieve the clamping and releasing action of the clamping jaws.