Abstract: This paper systematically reviews five decades of exploration in the field of microwave non-thermal effects, providing a comprehensive overview spanning conceptual definitions, experimental evidence, theoretical debates, and future directions. This review summarizes the key experimental achievements and disagreements in both the experimental and theoretical aspects, the experimental aspects include activation energy/pre-exponential factor measurements, isothermal controls, and in situ temperature measurements and the theoretical aspects include coherent electrical oscillations, radical pair/triplet mechanisms, and membrane noise limitations. The key point lies in proposing and expanding the "post-polarization effect" theoretical hypothesis, that is, through molecular dynamics simulations and quantum mechanics calculations, it has been confirmed that weak microwave fields can alter the collision patterns and energy distributions of polar molecules. This paper also identifies ongoing controversies (such as insufficient theoretical universality and the difficulty of completely ruling out thermal effects) and challenges within the field. We contend that the crux of the controversy lies in the absence of a single theory capable of explaining all phenomena, the fundamental constraints of quantum mechanics and thermodynamics that cannot be violated, and the experimental difficulty of completely excluding thermal pathways. Should non-thermal effects be definitively confirmed, they would have profound implications across multiple disciplines.