Check valve not prone to being jammed under high-temperature working condition

A check valve not prone to being jammed under the high-temperature working condition comprises a valve body, a valve clack, a valve rod and a valve rod sleeve. An airflow channel is arranged in the valve body, and a steam circulation opening inclining forwards is formed in the airflow channel. The valve clack is arranged in the airflow channel and located on the rear side of the steam circulation opening. The valve clack swings back and forth in the airflow channel so as to close or open the steam circulation opening. In the closed state, the valve clack is attached to and seals the steam circulation opening. In the opening state, the valve clack swings backwards and is separated from the steam circulation opening; the valve rod sleeve is fixedly arranged on the valve body, a through hole is formed in the valve rod sleeve in a penetrating mode, and the lower end of the through hole is a fillet. The valve rod is arranged in the through hole in an up-down sliding and penetrating mode, in the opening state, the