As global warming intensifies, high temperatures become one of the main factors leading to the declines in crop yields worldwide. Crop yields and sustainable agricultural development are severely constrained by heat stress. It is far from enough to improve crop tolerance to high temperatures only depending on the physiological response of plants. Rhizosphere microorganisms that closely interact with plants play an important role in plant development and stress tolerance, demonstrating great application potential. Focusing on the colonization of adaptive microorganisms under heat stress and the beneficial effects of microorganisms on plants, this article reviews the effects of heat stress on plant growth and the responses of plants to heat stress. Furthermore, this article clarifies the research status of microorganism-mediated crop tolerance to heat stress, which has guiding significance for the application of microorganisms in improving plant growth and crop tolerance to high temperatures.