The present invention relates to chemical reaction process of oxidizing alcohol with oxygen to prepare aldehyde or ketone, and is especially an alcohol oxidizing process with 2, 2, 6, 6-tetramethyl piperidine nitroxide free radical as catalyst. In organic solvent, and in the presence of catalyst comprising TEMPO, sodium nitrite and transition metal salt, alcohol is oxidized to produce aldehyde or ketone. The process has the alcohol, TEMPO, sodium nitrite and transition metal salt in the weight ratio of 100 to 1-5 to 1-10 to 1-10, oxygen pressure of 0.1-0.8 MPa, reaction temperature of 0-80 deg.c and reaction time of 1-24 hr. The present invention has the advantages of mild reaction condition, easy control, low cost, high safety and environment friendship.