Life extension platform structure has degenerated after suffering prolonged environmental erosion. It is difficult to observe platforms completely due to the limitation of objective conditions, so it is necessary to regard the life extension platform as a stochastic structure in tubular joint fatigue reliability prediction. Taking into consideration the fracture mechanics model, stochastic finite element method and compound random vibration theory, the fatigue life prediction method  for offshore platform tubular joint stochastic structure under stochastic wave load was proposed. The practicality and simplicity of the proposed method was proven by an example. The computational results proved that structural randomness had an effect on tubular joint fatigue life prediction.