Encarsia formosais a natural enemy of the invasive pestBemisia tabaciand is known to be a dominant parasitic. The frequency and magnitude of climate extremes, particularly temperature extremes, have increased, which has put insect populations at risk. However, the effects of temperature extremes onE. formosaare not well understood. To examine the impact of short-term extreme temperature exposure on the development and reproduction ofE. formosa, eggs, larvae, pupae, and adults were exposed to high/low temperature treatments (HLT25, HLT50, LLT25, and LLT50). Our findings indicate that the pupal stage ofE. formosaexhibited the strongest tolerance to both heat and cold, while adults exhibited a weaker tolerance. The shortest egg-to-adult development period of 12.65 days was observed inE. formosaexposed to HLT50treatment during the egg-larval stage. The parasitism peak of the adult stage was delayed by 1–6 days after exposure to extreme temperatures during the egg-larval stage. Conversely, the parasitism peak was advanced by 1–3 days after exposure to extreme temperatures during the pupal and adult stages. The eclosion rate, total parasitism, eclosion rate of the F1generation, and adult longevity of the F1generation were lower in the treatment groups than in the control groups. The F1generation’s development period was prolonged to 15.49 and 15.19 days after exposure to HLT25and HLT50treatments, respectively, during the egg-larval stage. The F1generation’s development period was shortened to 13.33 days after exposure to LLT50treatment during the pupal stage. Male individuals appeared in the F1generation after exposure to HLT50treatment during the pupal stage, with females accounting for only 56.38%. Our results demonstrate that short-term exposure to extreme temperatures has detrimental effects on the growth and reproduction ofE. formosa. In field biocontrol againstE. formosa, the release ofE. formosashould be avoided as much as possible when the ambient temperature is higher than 35°C or lower than 0°C. During extreme temperature conditions, timely supplementation and release ofE. formosapopulation, along with ventilation and cooling in greenhouse facilities during summer, are necessary for better pest control efficacy.