The rich firing behaviors of biological neurons enable the nervous system to execute complex computations, emulating which in hardware is advantageous for constructing advanced intelligent machines. Hodgkin–Huxley (H–H) neurons based on memristors feature great merits of high bio‐plausibility and low hardware cost. However, a universal design rule of memristive H–H neurons is still lacking, hindering its development and applications. Herein, a universal H–H neuron circuit structure is proposed and its feasibility based on NbOx memristors is demonstrated. The constructed neuron achieves 23 types of firing behaviors observed in biological neurons, simplifying the communication between neurons. To better understand the correlation between circuit parameters and firing patterns, the firing patterns into three classes according to the switching cycle ratio of two memristors are categorized. The circuit design rules of each category of firing patterns are deeply elucidated and universal regularities for tuning circuit parameters to implement the switch between different firing behaviors are presented. Finally, the potential applications of different firing behaviors in neuromorphic intelligence systems are discussed. This work provides theoretical guidance for engineering memristive H–H neuron circuits, assisting in building high‐order neuromorphic systems based on firing patterns.