Abstract: Based on the interaction of laser and dense plasma，discusses the trajectory of muon in mixture in femto-second laser field after muon catalysed fusion reaction. Here，deals with the mixture after muon catalysed fusion reaction as dense plasma，as the intervention of polarized laser beam，the muon drifts regularly. The results show that：when peak value of laser reaches 10²¹W/cm²，the muon has biggish drifts on the orientation of laser，it can penetrate the surface layer of the mixture，and separate from the fusion product，becomes to the free particle，the process is very short，much less than one laser pulse period. The same parameter laser intervention has very slight influence on other particles. On certain degree，it avoids the catalyst muon being catched by α -particle after catalysed fusion reaction and loses the catalytic ability，thus improves the catalytic efficiency.

Key words: muon, laser, dense plasma, trajectory