The invention discloses a paraboloid-groove-type solar concentrator capable of collecting rainwater. The solar concentrator adopts the structure that a water collecting basin (1) is mounted at the bottom of a reflecting mirror (2); a heat absorption pipe (3) is fixed on a supporting seat (6) through a heat absorption pipe bracket (4); the reflecting mirror (2) is fixed on the supporting seat (6) through a reflecting mirror bracket (5); particularly, the water collecting basin (1) is mounted at the back of the reflecting mirror (2) and the bottom of an end surface at the top of a paraboloid; one end of the water collecting basin (1) is connected to a rainwater collecting tank (8) through a filter (7); if the amount of precipitation is relatively large, the design that two ends of the water collecting basin (1) are both connected to the rainwater collecting tank (8) through the filter (7) can be adopted.