A continuous reaction system for preparing a ferromanganese oxalate precursor may comprise a first dissolution reactor, a second dissolution reactor, a first reactor, a second reactor, a material storage tank, and an ultrasonic reactor; the first dissolution reactor may be configured to accommodate a metal salt solution required for preparing the ferromanganese oxalate precursor, and the second dissolution reactor may be configured to accommodate a precipitant solution required for preparing the ferromanganese oxalate precursor; the first reactor may include a first feed port and a first overflow port, and the first feed port of the first reactor may be interconnected to a first discharge port of the first dissolution reactor and a second discharge port of the second dissolution reactor respectively through two pipelines.