Multi-area power balance affects the safe and stable operation of the power system. This paper presents an optimization strategy for multi-area DC dispatching control considering frequency constraints. Firstly, a multi-area joint dispatching model is constructed, which includes conventional unit constraints and power balance constraints. Secondly, in order to ensure the safety and stability of DC transmission, the minimum adjustment time and range of transmission line adjustment are set. Finally, a case study is carried out based on the load and power generation data of a two-area power system to verify the effectiveness and feasibility of the proposed strategy.