The invention relates to an intelligent irrigation and fertilization control system and control method. The intelligent irrigation and fertilization control system comprises a main control board and a group connected with the main control board and including a liquid level sensor, a soil moisture sensor, a rainfall sensor, a multi-way relay, an infrared remote controller, a network server and a power supply module for supplying power to the whole system. The intelligent irrigation and fertilization control system further comprises a solenoid valve and an agitator connected with the multi-way relay. The main control board comprises a controller unit and a group connected with the controller unit and including a clock circuit, a GPRS module, an infrared receiving module, a display module, a relay driving circuit, a human body infrared alarm module, and a sound alarm module. The infrared receiving module is used for receiving the infrared control signal of the infrared remote controller. A relay driving circuit is connected with the multi-way relay. A user can obtain and manage the information of the system by getting access to the network server through the network by using a cell phone or an Internet client, wherein the information includes time information, environmental information, equipment state information and control information. The intelligent irrigation and fertilization control system is simple and easy to realize, and achieves remote intelligent irrigation and fertilization and the specific irrigation and fertilization information through the network.