A semiconductor package structure and forming method thereof; the semiconductor package structure includes a heat sink frame (2) and a lead frame (1), where the heat sink frame (2) is connected with a heat sink (4), a chip pad (21) of the lead frame (1) is adhered with a chip (3), and the heat sink (4) is connected to the chip (3) through a bonding material (5), and where the lead frame (1) is provided with a first lead (22), and the heat sink frame (2) is provided with a second lead (43) and a third lead (44). The method of forming the semiconductor package structure comprises: arranging the second lead (43) and the third lead (44) on the heat sink (4), and connecting the first lead (22) to the bottom electrode of the chip pad (21) to form a current input terminal; connecting three second lead (43) on the heat sink frame (2) to the top electrode of the chip (3) to form a current output terminal; welding the third lead (44) on the heat sink frame (2) with a conductive wire to form a current control terminal, thus greatly reducing the use of conductive wires, and thus heat loss; and after injection molding, colloids are exposed on of both sides of the semiconductor package structure, thus realizing double-sided heat dissipation, and improving heat dissipation of the semiconductor package structure.