Based on the visible/near infrared diffuse reflectance spectroscopy technology, a portable nondestructive detector for red globe grape extraction multi-quality parameters in growth period was designed. The instrument included a spectrum acquisition probe, a spectrometer, a halogen lamp light source, a lithium battery, a controller and peripheral circuits. The size of the whole instrument was 200mm× 160mm×150mm, which was convenient to carry. The red globe grape extracted fruit grains in the growing period were selected as research objects, and visible/near infrared diffuse reflectance spectral information in the range of 400nm to 1000nm was collected, the original spectrum was preprocessed and the characteristic wavelength was extracted, and the optimal partial least squares regression (PLSR) prediction models of SSC, total acid, pH value, firmness and moisture content of red globe grape extracted fruits were respectively established. The correlation coefficients of the prediction set of the optimal PLSR prediction model for each index were 0.9545, 0.9778, 0.9878, 0.9456 and 0.9028, respectively, and the root mean square error was 1.0122°Brix, 2.0225%, 0.0747, 7.2813N and 0.9799%, respectively. Based on MFC development tools, instrument real-time analysis and processing software was written by C++ language, and the optimal PLSR prediction model with multiple quality parameters of red globe grape extract was implanted into hardware device, thus realizing one-touch non-destructive detection of multiple quality parameters of red globe grape extract during growth period. After inspection and testing, the predicted set and correlation coefficient of SSC, total acid, pH value, firmness and moisture content of red globe grape extracted fruit grains of the tester were 0.9414, 0.9687, 0.9768, 0.9348 and 0.9006, respectively. The root mean square error of the prediction set was 1.1567°Brix, 2.3645%, 0.0986, 8.3571N and 1.1051%, respectively. And the primary detection time of the detector was less than 2s. The results show that the instrument can realize the real-time nondestructive detection of red globe grape fruits during the growing period.