The invention relates to an improvement of an internal combustion engine cooling water pump, in particular to a flow-guiding type cooling water pump with an inner cavity in an arc surface structure. The flow-guiding type cooling water pump comprises a pump case, wherein a pump shaft is arranged in the bearing position of the pump case by using a bearing; the pump shaft is respectively provided with a transmission belt wheel, a water seal and impellers; an end cover is further arranged on the right side of the pump case; a water outlet hole is arranged on the end cover; particularly, the inner wall corner of the inner cavity of the pump case is in the arc surface structure; a flow guiding cone is arranged in the position, where a water outlet is, of the inner cavity of the pump case; and a flow guiding shade is arranged in the position where is at the right side of the water seal and in the inner cavity of the pump case. According to the flow-guiding type cooling water pump provided by the invention, the problems of large noise, low working efficiency and short impact abrasion service life of the water seal in the conventional internal combustion engine cooling water pump are solved, therefore the flow-guiding type cooling water pump is mainly used for the improvement of the conventional internal combustion engine cooling water pump.