The invention discloses a production process for smelting medium-low carbon ferromanganese through manganese sesquicarbonate ores. The production process comprises the following steps: mixing medium manganese slag containing furnace slag with a basicity of 1.1-1.3 and containing MnO with a content of 22-25%, charging the mixture into a shaking ladle and shaking, then charging a semi-finished alloy subjected to the shaking into an electric refining furnace and refining, and carrying out secondary desilicication; pouring the manganese sesquicarbonate ores, manganese ores and lime into the electric refining furnace filled with the shaked semi-finished alloy, adequately melting the manganese sesquicarbonate ores, the manganese ores and the lime through electric arc heating, carrying out smelting and sampling analysis, completely discharging the medium manganese slag and the medium-low carbon ferromanganese after the medium-low carbon ferromanganese meets product index requirements, and then charging the medium manganese slag into the shaking ladle and continuing to shake. The production process has the following advantages: the content of alloy phosphorus in the medium-low carbon ferromanganese can be effectively lowered by using the method for smelting the medium-low carbon ferromanganese; and the production cost is greatly lowered by replacing the use of low-phosphorous manganese ores.