A micro-fiber spectrometer based on non-symmertrical cross-czerny-turner optical structure is developed. In this spectrometer, the light signal collected and transferred by the fiber is dispersed by grating and then measured by a 2048-element line CCD array. The analog signals of CCD can be amplified and converted to digital signals by the data acqui-sition circuit of CCD that is based on the complex programmable logic device and PC104; the digital signals can be translated to the PC104 embedded industrial control block by the PC104 bus. The spectrometer and the data acquisition circuit of CCD have been integrated into a spectrometer module with physical dimensions of 96 mm (wide) ×104 mm (long) ×18 mm (high). Based on the PC104 bus, the spectrometer module and the PC104 embedded industrial control block can be in a cascade con-nection through the “needle” and “hole”. The spectrometer has such features as small volume, low power consumption, quick sample rate and excellent aseismicity among others, which make it suitable for field work under abominable conditions. The micro-fiber spectrometer has been used in an autonomous instrument for trace elements and nutrient measurement in seawater and the testing result is excellent.