An integrated optical acoustooptic tunable filter (AOTF)-based new type spectrometer is brought forward, and its characteristics are introduced in detail. Through analysis of the transmission functions, point spread function and dispersion power of the spectrometer detailedly, it is pointed out that the spectral resolution is proportional to acoustooptic interaction length L, and the square root of the number of stages. So the resolution can be enhanced more effectively by increasing acoustooptic interaction length L than increasing the number of stages. In addition, it is proposed that quasi-collinear acoustooptic coupling is a effective way to suppress sidelopes and improve the resolution of AOTF spectrometer. The testing the quasi-collinear device shows that as the acoustooptical coupling length is 25 mm and the angle between acoustical and optical waveguid is 0.42°, it is obtained that the measured FWHM is 1.44 nm when the acoustic frequency is about 174 MHz,the measured sidelobes level is -13.2 dB and the mode-conversion efficiency of 99%.