The invention discloses a sliding cover mechanism and a portable electronic device with the same. The sliding cover mechanism is used in the portable electronic device. The portable electronic device comprises a first shell and a second shell; the sliding cover mechanism comprises a sliding chute arranged on the first shell, a guide rail arranged on the second shell and matched with the sliding chute, at least one elastic member and a stop assembly, wherein the elastic member is arranged on the first shell and elastically supports against the second shell to ensure that the sliding cover mechanism is in a balance state; and the stop assembly is used for preventing the first shell from separating from the second shell. The elastic member of the sliding cover mechanism elastically supports against the second shell, therefore, the elastic member has little stress and long service life.