A method for encapsulating a part with plastic, said part having a first surface and a second surface, comprising: first, step 101: processing the first surface of the part to be encapsulated with plastic by using the surface mounting technology on the first surface; and after step 101 is performed, step 102: encapsulating, with plastic, the first surface of the part to be encapsulated with plastic; and after step 102 is performed, step 103: processing the second surface of the part to be encapsulated with plastic by using the surface mounting technology; and after step 103 is performed, step 104: encapsulating, with plastic, the second surface of the part to be encapsulated with plastic, wherein a specific step of the encapsulating the first surface with plastic comprises: placing the part to be encapsulated with plastic in a mould cavity of a lower mold (3.2), and combining an upper mold (3.1) and the lower mold (3.2); vacuuming the second surface through a vacuum suction hole at the bottom of the lower mold (3.2) to keep the plane of the second surface smooth; and injecting resin to the first surface through a resin injection hole on the upper mold (3.1) and finally solidating the first surface, and wherein a specific step of the encapsulating the second surface with plastic comprises: placing the part to be encapsulated with plastic in the mould cavity of the lower mold (3.2), placing the second surface of the part to be encapsulated with plastic under the resin injection hole on the upper mold (3.1), and combining the upper mold (3.1) and the lower mold (3.2); vacuuming the bottom of the first surface that is encapsulated with plastic through the vacuum suction hole at the bottom of the lower mold (3.2) to keep the plane of the bottom of the first surface that is encapsulated with plastic smooth; and injecting resin to the second surface through the resin injection hole on the upper mold (3.1) and finally solidating the second surface. first, step 101: processing the first surface of the part to be encapsulated with plastic by using the surface mounting technology on the first surface; and after step 101 is performed, step 102: encapsulating, with plastic, the first surface of the part to be encapsulated with plastic; and after step 102 is performed, step 103: processing the second surface of the part to be encapsulated with plastic by using the surface mounting technology; and after step 103 is performed, step 104: encapsulating, with plastic, the second surface of the part to be encapsulated with plastic, wherein a specific step of the encapsulating the first surface with plastic comprises: placing the part to be encapsulated with plastic in a mould cavity of a lower mold (3.2), and combining an upper mold (3.1) and the lower mold (3.2); vacuuming the second surface through a vacuum suction hole at the bottom of the lower mold (3.2) to keep the plane of the second surface smooth; and injecting resin to the first surface through a resin injection hole on the upper mold (3.1) and finally solidating the first surface, and wherein a specific step of the encapsulating the second surface with plastic comprises: placing the part to be encapsulated with plastic in the mould cavity of the lower mold (3.2), placing the second surface of the part to be encapsulated with plastic under the resin injection hole on the upper mold (3.1), and combining the upper mold (3.1) and the lower mold (3.2); vacuuming the bottom of the first surface that is encapsulated with plastic through the vacuum suction hole at the bottom of the lower mold (3.2) to keep the plane of the bottom of the first surface that is encapsulated with plastic smooth; and injecting resin to the second surface through the resin injection hole on the upper mold (3.1) and finally solidating the second surface. placing the part to be encapsulated with plastic in a mould cavity of a lower mold (3.2), and combining an upper mold (3.1) and the lower mold (3.2); vacuuming the second surface through a vacuum suction hole at the bottom of the lower mold (3.2) to keep the plane of the second surface smooth; and injecting resin to the first surface through a resin injection hole on the upper mold (3.1) and finally solidating the first surface, and wherein a specific step of the encapsulating the second surface with plastic comprises: placing the part to be encapsulated with plastic in the mould cavity of the lower mold (3.2), placing the second surface of the part to be encapsulated with plastic under the resin injection hole on the upper mold (3.1), and combining the upper mold (3.1) and the lower mold (3.2); vacuuming the bottom of the first surface that is encapsulated with plastic through the vacuum suction hole at the bottom of the lower mold (3.2) to keep the plane of the bottom of the first surface that is encapsulated with plastic smooth; and injecting resin to the second surface through the resin injection hole on the upper mold (3.1) and finally solidating the second surface. placing the part to be encapsulated with plastic in the mould cavity of the lower mold (3.2), placing the second surface of the part to be encapsulated with plastic under the resin injection hole on the upper mold (3.1), and combining the upper mold (3.1) and the lower mold (3.2); vacuuming the bottom of the first surface that is encapsulated with plastic through the vacuum suction hole at the bottom of the lower mold (3.2) to keep the plane of the bottom of the first surface that is encapsulated with plastic smooth; and injecting resin to the second surface through the resin injection hole on the upper mold (3.1) and finally solidating the second surface.