The work aims to analyze the advantages and disadvantages of the existing ink supply system, and propose a design scheme of remote ink fountain system based on STM32 to solve the problem of insufficient ink volume in the digital ink supply system of domestic offset printing presses. The mechanical structure of the zoning ink fountain was adopted to control the opening degree of the ink key independently. The ink key motor drive hardware system based on STM32F103 MCU was constructed. The 6-bit DIP switch was used to distinguish different drive boards. The feedback pulses from magnetic encoder were counted to control the position of the ink key. The panel buttons and display unit of the console were designed and the ink key position adjustment was divided into 0~99 positions. CAN bus was adopted for communication between systems. The ink key position and status information were displayed on the console panel and the host computer monitoring interface in real time. The experimental results indicated that the remote control ink fountain system adjusted the ink key opening range from 0.05 mm to 0.6 mm. The ink key positioning accuracy was about 5 μm and the repeated positioning accuracy was well. The remote ink fountain system based on STM32 realizes the precise adjustment of the ink volume during the printing of the offset press. The system runs stably, meets the current digital ink supply requirements for offset presses, and has great application value.