The invention discloses a method, apparatus and device for determining the step pitch of a tunnel excavation inverted arch and a storage medium. The method comprises the following steps: inputting data in historical engineering design and detailed construction data; calculating a safety critical value of surrounding rock deformation by using a creep aftereffect theory; obtaining inverted arch steppitch corresponding to the surrounding rock level and data of inverted arch primary excavation length; establishing a tunnel safety evaluation three-dimensional model; inputting rock detection data acquired in an excavation site of an excavation target tunnel into the tunnel safety evaluation three-dimensional model; calculating the surrounding rock level of the target tunnel excavation site; outputting inverted arch step pitch, inverted arch primary excavation length and excavation day number data; obtaining a tunnel safety evaluation three-dimensional model through calculation and analysisof historical data, inputting rock detection data of a target tunnel excavation site into the model, and obtaining range data of inverted arch step pitch and inverted arch primary excavation length, thus effectively guaranteeing tunnel safety and high-quality and efficient construction.