A femoral marrow inside pin and rapid aiming device comprises a grip, an aiming guide rod, a remote end locating support, a locking screw, a guide lever, and a femoral marrow inside pin, a femoral fixed-depth rod, a femoral drill bush and a drill bush tube. The guide lever is firmly connected with the grip, while the femoral marrow inside pin is connected with the locking screw in a threaded joint. The utility model also consists of a fixed-length ratchet, a supporting plate, a spring and locating sleeve, wherein the locating sleeve is inserted onto the remote end locating support and the femoral fixed-depth rod is inserted into the locating sleeve and the front part of the femoral fixed-depth rod is supported against the femoral marrow inside pin. A plurality of grooves with different depths that are matched with the ratchets of the fixed-length ratchet and the supporting plate can be inserted onto the remote end locating support in a sliding way and then firmly connected with the fixed-length ratchet. One end of the spring is supported against the remote end locating support, while the other end is supported against the supporting plate. The utility model is convenient for operating and high in locating precision, and especially one femoral fixed-depth rod can be applied for multiple purposes and suitable to the marrow inside pin with different diameters.