Outer-sliding-sleeve-closeable switch

The utility model discloses an outer-sliding-sleeve-closeable switch which is composed of an upper connector, an outer sliding sleeve, a spring and a lower connector. The upper connector is connected with the lower connector in a threaded mode. A conical surface ball seat is arranged in a center through hole in the upper connector. The outer pipe wall of the upper connector is provided with an outer step-shaped shoulder, the middle pipe wall is provided with a liquid outlet hole, and the lower pipe wall is provided with a pressure transfer hole. The middle of the inner pipe wall of the outer sliding sleeve is provided with an annular table face, and the upper portion is provided with a liquid discharge hole. The outer sliding sleeve is connected to the outer pipe wall of the upper connector and the outer pipe wall of the lower connector in a sleeving mode. A spring is arranged on the position, on the lower end face of the sliding face, of the lower connector in a sleeving mode and fixed through an adjusting ring. The outer-sliding-sleeve-closeable switch is not affected by pressure and impact in a pipe column and reliable in sealing, a steel ball is fished out after separate layer fracturing and separate layer acidizing are finished, and separate layer water injection or separate layer oil production can be conducted directly without opening the pipe column.