The invention discloses a bus-based seawater desalination control system. In the prior art, the heat collection efficiency is low, the water production rate is low, and the system is completely in a spontaneous extensive state, so that the requirements for practical application can not be met. The seawater desalination control system comprises a light gathering and heat collection part, a heat accumulation and heat exchange part, a seawater desalination part, an analog input module, a remote I / O (input / output) module, a PROFIBUS bus, a frequency converter, a PLC (programmable logic controller), and an upper computer, wherein a flow transmitter, a pressure transmitter, a temperature transmitter and a liquid level transmitter acquires signals and input the signals into the analog input module; the analog input module is connected with the remote I / O module; the remote I / O module is connected with the PLC through the bus; the PLC is connected with the upper computer through RS485; and the PLC simultaneously controls the frequency converter via the bus through the remote I / O module. The invention is simple in structure, stable in system, convenient to maintain, mature in technology, favorable in control effect and low in cost.