This paper presents a novel yet high performance diascopic illumination configuration for simultaneously detecting cells of different sizes and different fluorescence labeling in a microfluidic chip. An objective-type dark-field condenser equipped with a low-cost tungsten bulb light source with continuous wavelengths (400 to 900 nm) and an UV-Vis-NIR spectrometer is used for detecting the multispectral signals from various particles and cells. With this approach, continuous cell counting and spectra analyzing are realized in a single channel without using any spatial filter and delicate optical detectors. Results show that the developed system is capable of identifying different labeled particle and cell samples by extracting the information side-scatter, absorption, and fluorescence from the information-rich spectra. This proposed system provides an efficient multi-color detection for identification and classification on a micro-flow cytometer chip.