The invention discloses a method and a device for detecting in-place closing of a car presser. The method comprises the steps as follows: detecting the stress value T1 of a steel structure of the car presser; and comparing the stress value T1 with a preset stress value T2, and if T1 is not less than T2, confirming that the car presser is closed in place. Through the method, the car presser can be accurately and reliably detected whether to be closed in place or not so as to guarantee that a car dumper runs normally and safely.