Bright squeezing in multiple discrete frequency modes is important to implement quantum-enhanced spectroscopy and optical quantum computing applications. Here, we propose a way to achieve topologically protected squeezing through the down-conversion process in the Su-Schrieffer-Heeger model along synthetic frequency dimension. The edge states localize the squeezing at the frequency boundary modes, protecting the squeezed light from the perturbations and supporting tunable squeezed modes. Moreover, our model can lead to broadband bright squeezed frequency comb, inducing the multipartite entanglement between the comb line modes with the robustness. Our proposal suggests the generation of a topologically-protected multimode bright squeezing, which gives an important platform for exploring topological multipartite entanglement for robust clusterstate generation.