The invention relates to a computer-based intelligent environmental control system of greenhouse. The computer-based intelligent environmental control system comprises a sensor group, a wireless communication module, a microcontroller, a remote terminal, control equipment, a crop monitoring module and a pesticide spraying device, wherein the crop monitoring module comprises a high-definition camera, an infrared detector and a warning unit, the pesticide spraying device is arranged at the top of the greenhouse, a solenoid valve is arranged at the pesticide spraying device, the sensor group is connected with an input end of the microcontroller, an output end of the microcontroller is connected with control equipment, the remote terminal is wirelessly connected with the microcontroller by thewireless communication module, the crop monitoring module is connected with an input end of the microcontroller, the solenoid valve is connected with an output end of the microcontroller. By the system, an environmental parameter in the greenhouse can be monitored in real time and controlled remotely, meanwhile, the crop growth state can be monitored in real time, pesticide can be automatically sprayed to kill insects when insects on crop are monitored, the insects are timely handled, and the crop growth is effectively guaranteed.