The invention discloses a finishing rolling unit in ESP endless rolling and a rolling method, and belongs to the field of steel and iron material engineering. The finishing rolling unit in the ESP endless rolling of the invention comprises a plurality of finishing mills arranged in the order of a finishing rolling process, and is characterized in that one of the finishing mills is a standby finishing mill for replacing the worn finishing mill; a spray header is arranged in front of the preceding finishing mill in the standby finishing mill and the worn finishing mill by the order; and the spray header spray cold water to cool a strip plate to complete the transformation process of austenite to ferrite. According to the invention, the full-continuous non-stop flexible rolling technology canbe realized, the productivity drop caused by the forced stop of the production line due to the downtime and roll change of the finishing rolling unit is avoided, and the output is also improved; andthe roll temperature rise can be reduced, so that the fatigue cracking and fracturing of the roll due to the thermal stress are reduced, the wear of the roll is reduced, the surface quality of endlessrolled products is improved, and the production cost is significantly lowered.