The invention discloses an automatic acid supply system of ceramic filters. The automatic acid supply system comprises a total acid storage barrel, a total acid pump, a partial acid storage barrel, apartial acid pump, a programmable logic controller (PLC) system and at least one pneumatic valve, wherein the total acid storage barrel, the total acid pump, the partial acid storage barrel and the partial acid pump are sequentially connected through pipelines; the partial acid pump is connected with the at least one pneumatic valve; each pneumatic valve is connected with a ceramic filter; and a first liquid level detection device is arranged in the partial acid storage barrel. The PLC system is used for receiving a liquid level value detected by the first liquid level detection device; when the liquid level value is lower than or equal to a preset value, the PLC system opens the total acid pump until the liquid level in the partial acid storage barrel reaches the preset value; and the PLCsystem is used for opening the partial acid pump and the corresponding pneumatic valve when receiving a cleaning instruction, wherein the pneumatic valve can be started at a delayed preset time afterthe partial acid pump is started. According to the invention, acid supply equipment can be reduced, acid supply pipelines can be optimized, and safety and reliability of the acid supply system can beimproved.