To guide the formulation design of thermobaric explosive(TBE) and study the relationship between TBE energy output, TBE component and experimental atmosphere, the energy output characteristics of TBE were analyzed via the shock wave energy, bubble energy and total energy, using an underwater explosion test method. Results show that under the experimental conditions, the shock wave energy and total energy of TBE with the aluminum powder content of 40% are maximum, their values are 338.27, 2549.84 kJ, respectively. The bubble energy of TBE with the aluminum powder content of 50% is maximum, its value is 16.08 kJ·g^-1. The oxygen content is an important factor affecting the energy output of TBE.