As a Digital PCR (dPCR) technology, an updated iteration of traditional PCR technology with absolute quantification, has great potential in biological fields such as neo-coronavirus nucleic acid sequence detection and cancer cell detection. Existing dPCR fluorescence detection systems are challenging to make a reasonable trade-off between detection throughput, detection speed, and cost. The small imaging field of view and multiple image stitching greatly limit the accuracy and detection time of dPCR fluorescence detection systems. Therefore, a digital PCR detection experimental platform is builded with multi-channel based on a large field-of-view fluorescence microscope system. Rely on this platform,By simulation experiments of Zemax to improve the design of microscopy objective, Relying on this experimental platform, Zemax software is used to optimize the system structure and improve the design of microscopic objectives, which can realize an 18mm full field of view and 6.3μm resolution among the FAM、HEX、ROX channels. By using the Randomized Hough transform algorithm (RHT), the microfluidics chip including the normal "holewell" structure、the new structure such as "snowflake", "branch" and other Irregular structures can be obtain a clear and stable fluorescence images under the premise of a large field of view and fast detection.