High temperature-resistance external casing packer

The invention provides a high temperature-resistance external casing packer, which is characterized by comprising an upper connector, a primary liquid tank, a first rubber bucket, a second rubber bucket, a secondary liquid tank, a third rubber bucket, a tertiary liquid tank and a lower connector, wherein the upper connector and the lower connector are connected with oil pipes up and down respectively; one end of the primary liquid tank is connected with an upper connector and the other end of the primary liquid tank is connected with the first rubber bucket; one end of the tertiary liquid tank is connected with the lower connector and the other end of the tertiary liquid tank is connected with the third rubber bucket; the first rubber bucket and the second rubber bucket are tightly connected by a retaining ring; and the secondary liquid tank is used to connect the second rubber bucket and the third rubber bucket. In the high temperature-resistance external casing packer, two layers ofreinforcing rubber bucket