The invention discloses a device capable of achieving signal light coupling and aligning monitoring for a chip type spectrograph, and belongs to the technical field of optical imaging. In the prior art, the coupling efficiency is low. A collimating mirror, a transmission reflecting prism and a coupling imaging lens are sequentially arranged to form a signal light coupling optical system by sharingthe same optical axis, a coupling imaging lens, a transmission reflecting prism and a monitoring imaging lens are sequentially arranged to form a signal light aligning monitoring optical system by sharing the same optical axis; in the signal light coupling optical system, the optical axis is turned by 90 degrees at the working mirror surface of the transmission reflecting prism, and the includedangle formed between the working mirror surface and the optical axis is 45 degrees, and signal light from the collimating mirror is reflected to the coupling imaging lens through the working mirror surface; in the signal light aligning monitoring optical system, signal light from the coupling imaging lens is transmitted to the monitoring imaging lens through the working mirror surface of the transmission reflecting prism; a light sensitive surface of a photoelectric detector is located at the image surface of the monitoring imaging lens, and the photoelectric detector is connected with a displayer.