The catalytic oxidizer assembly(COA)is an important part of the trace contaminant control subassembly in manned spacecraft. Temperature control in COA via a new self-tuning fuzzy logical controller (FLC)is analyzed in this paper. The new tuning method applies the bang-bang on-line tuned method to the design of the self-tuning FLC for obtaining the system parameters. On the basis of these parameters, the input and output scaling factors are calculated with simple tunable formulas. Then the proposed self-tuning FLC is realized by combining the scaling factors and the normal look-up table. It can realize self-tuning parameters,  and simplify the design. Simulation results show that the proposed self-tuning FLC is fit for controlling the temperature of COA and isn't sensitive to parameter changes.