Technological diversification is one of the important means for firms to improve the core competitiveness, and there are some differences in the stabilizing effects of technological diversification strategies on firm performance in different industry contexts. Using IPC invention patent information data of 710 GEM companies from 2009 to 2018, based on industry characteristics and industry concentration perspective using a fixed panel model, the relationship between technological diversification and corporate performance fluctuations were explored. It is found that: Technological diversification has a significant smoothing effect on corporate performance fluctuations; The smoothing effect of technological diversification on corporate performance is relatively strong in high-tech industries; Technological diversification facilitates relatively strong smoothing of corporate performance fluctuations in the case of low industry concentration, while the smoothing effect is nearly ineffective in the case of high industry concentration. It provides an important basis for the construction of technological knowledge infrastructure of enterprises, and also provides scientific theoretical guidance for the construction of technological ecology of diversified industries in different industry contexts.