In view of the current problems in the scale of chicken farms, such as the complex environment, the large number of monitoring parameters, the poor realtime monitoring capability and the low degree of automation of control equipment, A multiparameter monitoring and control system based on programmable logic controller (PLC) was designed to monitor the environment of the scale chicken farms in real time. The sensor transmitted the collected information to the PLC via the RS485 bus, After treatment and sent to the host computer, The host computer carried on the analysis, the processing, the storage to the data which transmitted, and carried on the comparison with the hypothesis value, The corresponding control instruction was sent to the PLC, Control the ventilation system and other related control equipment start and stop. Experimental results show that, The system operates stably, Rapid response, The temperature, humidity and ammonia concentration can be well detected and the related equipment can control these parameters in the appropriate range, To ensure the healthy growth of broilers, with a certain value of market promotion.