Aircraft icing is one of the important factors affecting flight safety, while civil aircraft need to find the icing area and the appropriate time that satisfy the Airworthiness regulations in order to complete the natural icing flight tests. This paper analyzes the pattern of icing events in Northeast China from March 2021 to February 2022 by using the PIREPs, and analyzes the weather characteristics based on the ERA5 hourly reanalysis dataset in the same period. The results show that: most of the aircraft icing events in Northeast China occur in spring, and the height of icing varies in different seasons. The weather system is mostly the Northeast Cold Vortex and upper-level trough. Low-level icing often occurs in the Cold front. Mid-level icing often occurs in the southwest warm-moist airflow in front of the trough. High-level icing often occurs near the trough line. We provide a weather forecast model for icing in Northeast China and a cloud tracking strategy for conducting the natural icing flight tests.