Device and method for testing compression amount of pile body of rock-socketed cast-in-place pile

The present disclosure provides a device and a method for testing the compression amount of a pile body of a rock-socketed cast-in-place pile. The testing device comprises open flexible pipes which are correspondingly bound with two main reinforcements in the pile body of the rock-socketed cast-in-place pile, and the lengths of the open flexible pipes are the same as those of the bound main reinforcements; one end of each of the two open flexible pipes is located at the bottom end of the corresponding main reinforcement and fixedly connected with a first sealing sheet, and the other ends of the two open flexible pipes are located at the pile block of the rock-socketed cast-in-place pile and fixedly connected with second sealing sheets; a closed rigid pipe is located in the open flexible pipe, pipe bodies of the closed rigid pipe and the open flexible pipe are not in contact.