The invention relates to a cooler for a steel strip continuous annealing furnace. The cooler is positioned at the tail end of a continuous annealing furnace and communicated with the continuous annealing furnace. The cooler for the continuous annealing furnace comprises an underframe, wherein a muffle tube which is communicated with the hearth of the continuous annealing furnace is arranged on the underframe; the muffle tube is provided with a hearth roll assembly which is used for bearing a steel strip and can synchronously move with the steel strip; a cooling water jacket is sheathed on theouter wall of the muffle tube; the hearth roll assembly is connected with the muffle tube after penetrating through the cooling water jacket; the shell of the cooling water jacket is connected with the underframe through a rolling shaft bracket; and the cooling water jacket is provided with a water inlet and a water outlet, and communicated with an external cooling water circulation pipe network through the water inlet and the water outlet. The on-site test indicates that compared with the prior art, the cooler provided by the invention has the advantages of favorable use effect, low manufacturing cost, obvious energy-saving effect and low operation noise, can meet the requirements for technical cooling, and can be used on continuous annealing lines for producing various steel strips, such as silicon steel, cold-rolled strip steel, stainless steel and the like.