An electrolyte, an electrochemical device thereof, and an electronic device thereof are provided. An electrolyte includes vinylene carbonate and a carboxylate-based compound. Based on a mass of the electrolyte, a mass percentage of the vinylene carbonate is A %, a mass percentage of the carboxylate-based compound is B %, and the electrolyte satisfies: a value of A/B ranges from 0.1 to 10, and a value of A+B ranges from 1.1 to 6. In the electrolyte provided by the disclosure, the film formation on the surface of the negative electrode is improved, and the internal resistance is optimized. In this way, the electrochemical device exhibits good cycle performance at high temperature and room temperature and favorable capacity performance at high temperature and achieves low internal resistance.