A method is proposed for determining the energy release in a combustible mixture, which is based on processing the trajectory of the expanding wave from the viewpoint of the strong explosion model. The wave trajectory in the case of critical initiation of multifront detonation in a combustible mixture is compared with the trajectory of a blast wave generated by the same initiator in an inert mixture whose gas-dynamic parameters are equivalent to those of the combustible mixture. The energy release is defined as the difference between the joint energy release of the initiator and combustible mixture in the case of critical initiation and the energy release of the initiator in the case of blast wave excitation in the inert mixture. Results of experimental validation of the method by an example of a stoichiometric acetylene–oxygen mixture are presented. Noticeable deviations of the experimental profile of energy release from available model concepts are observed.