An infrared thermal imager and an OpenMV machine vision module provided in a data acquisition device are used to collect crop surface temperature data and image data, respectively, and transmit the data to a computer for processing by a Raspberry Pi module via a wireless transmission module. After reading the image data, the computer obtains color components and growth parameters of the crop, and merges the color components and temperature data to assist in building an early warning model. The system and method enable real-time, continuous and nondestructive monitoring of crop growth information to provide references for adjustment and control of greenhouse environmental parameters.