Display omitted •The effect of temperature rises and falls on anaerobic digestion was assessed.•45 °C exhibits optimal methanogenic performance during temperature rises and falls.•An effective equilibrium between hydrolysis and methanation is achieved at 45 °C.•The shortest recovery time was 2 days following temperature fluctuation. This study implemented five successive temperature stages (35 °C–45 °C–55 °C–45 °C–35 °C) in a continuous stirred tank reactor, designated as D35-1, D45-1, D55, D45-2, and D35-2, respectively. The objective was to probe the mechanism of temperature transformations on methanogenesis performance, microbial community, and metabolic pathways. The suitability of 45 °C for anaerobic digestion (AD) under varying temperatures was emphatically expounded. Intriguingly, optimal methanogenesis performance was attained at 45 °C, with methane production reaching 238.51 mL/g VS/d in D45-1 and 245.91 mL/g VS/d in D45-2, signifying increases of 17.66% and 21.32% contrasted with D35-2, respectively. Additionally, considerable resistance to temperature shocks at 45 °C was also manifested, as evidenced by a recovery time of 2 days in D45-2. At 45 °C, an effective balance between hydrolysis and methanogenesis was observed, maintaining a dynamic equilibrium between acetoclastic and hydrogenotrophic methanogenesis. The primary drivers in D45-1 were Caldicoprobacter, Bathyarchaeia, and Methanosarcina, while Anaerolinea and Methanosarcina were the key determinants in D45-2. By contrast, methanogenesis was suppressed at other stages. Therefore, 45 °C emerges as a viable alternative to conventional temperatures when confronted with temperature fluctuations to optimize energy efficiency. The results provide novel insights into AD temperature management and pave the way for engineering applications.