Based on the nonlinear evolution equation of optical field in a single microcavity, the evolution equation for cascaded dual microcavities is derived, and the characteristics of the intracavity optical field and the impact of initial pulse on the optical field are analyzed when the dispersions in the two microcavities are opposite. The theoretical analysis results indicate that the cascaded dual microcavities not only increase the degrees of freedom for parameter selection but can also output optical frequency combs with different characteristics from the two microcavities. This can significantly enhances the generation and utilization efficiency of microcavity frequency combs. By adjusting the width, amplitude, and phase of the initial pulse, the number and position of intracavity solitons can be controlled. This work is of reference significance for generation and modulation of stable optical solitons in dual microcavity structures.