The invention discloses a redundancy output digital quantity output module based on a special-purpose CPU. The module comprises an onsite IO connecting seat, a power solid-state relay, an optical coupling isolator, a multiplexer, a master controller, an etherCAT protocol stack chip and a board base connector. According to the invention, a CPU made in China is taken as a master controller. The module provided by the invention has the following advantages: the module has redundancy output, load short-circuit protection, overt-temperature protection and under-voltage turning-off functions, employs an industrial grade high-reliability lightening-proof anti-strong-electromagnetic high-frequency interference circuit design, is low in cost, good in heat dissipation and stable and reliable in performance, employs a patch type chip and components, can be adapted to various industrial fields with large electromagnetic interference and severe environment and can be stably applied to working occasions of arcing currents, welding currents and frequency converters. A data dual-protection function is exhibited, redundancy output is realized, even if a CPU in a circuit is shutdown, DO data can also be output, and thus output of important control signals is guaranteed.