The invention discloses an ejector with a spray nozzle position adjustable and a device. The ejector with the spray nozzle position adjustable comprises a primary flow tube, a spray nozzle, a receiving chamber, a secondary flow tube, a blending chamber and a diffusion chamber. An expansion device with the length varying along variation of pressure is arranged at the joint of the primary flow tube and the spray nozzle. The primary flow tube, the expansion device, the spray nozzle, the blending chamber and the diffusion chamber are sequentially connected along the axis. The spray nozzle position of the ejector is automatically adjusted simply through variation of the flow rate of primary flow, the performance of the ejector is changed accordingly, and the ejector can have good performance under different working conditions.