To develop high performance sealing material for Stirling engine, the blend composites of polyphenyl ester-polytetrafluoroethylene were prepared by cool-pressing and hot-sintering. The effect of potassium titanate whisker (PTW) and calcium sulfate whisker (CSW) on the tribological properties of the POB-PTFE composites was investigated. The results showed that POB-PTFE composites could be used as the matrix of seal material in Stirling engine. The creep and shear resistance of the POB-PTFE composites are improved by the addition of PTW, the friction coefficient of the composites did not be changed with the variation of load, meanwhile the wear resistance remain relatively stable. The friction coefficient of the composites did not vary with the variation of velocity when the content of PTW is less than 5% either. The POB-PTFE composites filled with PTW is an optimized sealing material for Stirling engine, but the composites filled with CSW is inadequate to cope with the special requirements for heavy load and high sliding velocity.