The present invention relates to a safety lever system in a cab of an excavator, which is capable of preventing an unintended descending of a control box without the operation of the safety lever, and promoting a safer tilting of the control box through a limit means that controls the power application/short-circuit. According to the present invention, if the operator tilts the control box to get in or get out of the cab, the safety lever system shunts (i.e., short-circuit) the power of the control lever or the control box. Therefore, the possibility of malfunction of the excavator due to the miss-operation of the operator is very slim, and the control box cannot be returned to its original position unless the operator operates the safety lever again. This structural improvement of the safety lever eliminates a possibility of the malfunction of the excavator due to the operator's mistake, and markedly increases the reliability of the excavator.