The invention discloses a line parameter calculation and data control method within a regional dispatching range. The line parameter calculation and data control method comprises the following steps: (1) collecting line routing information in an application; (2) in an Access database system, establishing a calculation model according to the voltage level and different line parameters, and achieving conversion between an actual value and a per-unit value; (3) automatically identifying different branches of a line, and according to the types of the branches, summing the different branches; (4) through converted data, automatically completing superposition and classified display according to the branch condition of the line, and according to the line routing change condition, entering parameters in real time, automatically completing sectional parameter calculation and concluding the overall condition of the line; (5) during line cutting transformation, needing to synchronously add or delete the line parameters; and (6) retrieving and querying by using keywords. By the line parameter calculation and data control method, complex and cumbersome link during conventional manual mapping and multi-level verification is avoided, the expandability is strong, and use and transmission are convenient.