The traditional biochemical detector exhibits poor adaptability, inconvenient carrying and slow detection, which can’t meet the needs of first-aid under field condition like natural or man-made disasters etc. Therefore a scheme of first-aid biochemical detector based on MOMES Micro Spectrometer, UV LED and Photodiode was proposed. An optical detection structure combined continuous spectrum sweep with fixed wavelength measurement was designed, which adopted mobile detection optical path consisting of Micro Spectrometer and Halogen Lamp to detect Chloride (Cl-), Creatinine (Cre), Glucose (Glu), Hemoglobin (Hb). The UV LED and Photodiode were designed to detect Potassium (K-), Carbon dioxide (CO2), Sodium (Na+). According to the field diagnosis and treatment requirements, we designed the embedded control hardware circuit and software system, the prototype of first-aid biochemical detector was developed and the clinical trials were conducted. Experimental results show that the sample's absorbance repeatability is less than 2%, the max coefficient of variation (CV) in the batch repeatability test of all 7 biochemical parameters in blood samples is 4.68%, less than the clinical requirements 10%, the correlation coefficient (R2) in the clinical contrast test with AU5800 is almost greater than 0.97. To sum up, the prototype meets the requirements of clinical application.