The invention relates to a built-in foldable fish hand net, comprising a hoop connecting piece, a handle, a foldable main frame, a net pipe and a locking structure; the foldable main frame comprises a No. one foldable main frame and a No. two foldable main frame, the locking structure is connected with the handle, the foldable main frame further comprises a directional shaft sleeve, the directional shaft sleeve is fixed in the No. one foldable main frame, the No. two foldable main frame is sleeved on the directional shaft sleeve and installed on the directional shaft sleeve in a rotational manner, the handle is installed in the directional shaft sleeve, the No. two foldable main frame is provided with a main frame hole, the directional shaft sleeve is provided with a directional hole, and when a No. one net pipe and a No. two net pipe are completely in an open state, the main frame hole and the directional hole are mutually connected; when the locking structure is clamped in the main frame hole and the directional hole simultaneously, the locking structure limits the movement of the handle, the No. two foldable main frame and the No. one foldable main frame. According to the built-in foldable fish hand net, the volume is greatly reduced during storage and transportation, meanwhile, the operation is convenient during use, and the built-in foldable fish hand net has the advantages of stable structure, fastness, reliability and the like.