In this paper, companion model method is applied to establish a basic filter model for electromagnetic transient simulation. Based on the requirements of real-time simulation in the converter station, this paper proposes a simplified filter model and analyzes the speed-up ratio for model optimization. Simulation result shows that under the presupposition of ensuring calculation accuracy, the simplified model can evidently improve the calculation efficiency and play an important role in the realization of real-time electromagnetic transient simulation in the converter station.