Provided are a locking steel plate and a locking steel plate assembly with the locking steel plate. Herein, the locking steel plate may include a steel plate body, an elastic block hook and a limit groove. The steel plate body is provided with a mounting hole, and the mounting hole may include a first hole section and a second hole section having a cross section area less than that of the first hole section. The elastic block hook is provided inside the first hole section, a first end of the elastic block hook is connected with the steel plate body, and a second end of the elastic block hook bends toward the second hole section. The limiting groove is provided on an inner wall of the second end of the elastic block hook. With the adoption of the technical solution of the application, inconvenient operation caused when an additional assembly prevents the locking steel plate from getting loose in the related art may be effectively solved.
