The invention relates to a method for determining the amount of a slagging material and deoxidized alloy added into an LF refining furnace by use of a reference heat method. The method comprises the following steps: controlling the amount of slags discharged from a rotary furnace during a refining process, wherein the amount of the added synthetic slags is the same during a steel discharging process of the rotary furnace according to the same type of steel heat number; (1) acquiring data and building a database by use of a computer; and (2) using the database for determining the amount of the slagging material and the deoxidized alloy added into this type of steel LF refining furnace when the acquired data of a certain type of steel in the database is accumulated to be not less than 400 heat number. The method disclosed by the invention comprises steps of acquiring operation data, building the database and using the computer to process the data rapidly and accurately; the reference heat method absolutely can be used for replacing the existing slagging method for manually determining the amount of the added slagging material and has the advantages of solving the instability of manual determination, optimizing the refining effect, stabilizing the quality of refined liquid steel and promoting standardized operation.