Abstract: In order to further understand the fuel atomization mechanism in scramjet combustor, the atomization of cross liquid jet in a Ma=1.94 supersonic flow was investigated numerically. Euler-Lagrange method was used for calculation, and K-H/R-T model was used for secondary breakup. The calculation results reveal that when secondary breakup is considered, the spray penetration depth and distribution of droplet velocity obtained by spray cone model agree well with the experimental results. The initial droplet diameter has little effect on the spray penetration depth and droplet distribution. With the increase of the initial spray cone angle, the spray penetration depth on the same cross section decreases gradually. When secondary breakup is not considered, the spray penetration depth and droplet distribution are greatly related to the initial droplet diameter.