The invention discloses a semi-open type centrifugal pump impeller with L-shaped blades and a centrifugal pump using the same. The impeller comprises the blades and a rotary plate. A shaft hole allowing a driving shaft to penetrate through is formed in the center of the rotary plate. The blades are evenly fixed to the rotary plate around the axis of the shaft hole. The blades comprise the high blades and the low blades. The high blades and the low blades are arranged at intervals and are equal in number. Each high blade comprises a high blade shaft hole close section and high blade shaft hole far section which are connected. The cross section of each high blade shaft hole far section is in an inverted-L shape. Each high blade shaft hole far section comprises a first part perpendicular to the rotary plate, and a second part parallel to the rotary plate. A groove-shaped cavity of which an opening faces the rotation direction of the rotary plate is formed between each second part and the rotary plate. The lift and flow passing capacity of the centrifugal pump using the semi-open type centrifugal pump impeller with the L-shaped blades are improved.