The utility model discloses a locomotive microcomputer control device based on output drive hot redundancy and reconnection control. The locomotive microcomputer control device includes a microcomputer controller, more than two sets of plug-in units, and a switching drive circuit component. Drive programs of a key contact group on a locomotive, which are used for driving the key contact group, are stored in each plug-in unit; the microcomputer controller detects the real-time states of the above key contactor group in a real-time manner and performs analysis judgment. If an abnormal situation occurs, the microcomputer controller switches off a current-operation plug-in unit and switches on any one of the rest idle plug-in units through the switching drive circuit component so as to drive the key contact group. The locomotive microcomputer control device of the utility model has the advantages of simple and compact structure and easiness in implement; with the locomotive microcomputer control device adopted, a problem of low reliability in single locomotive/multi-locomotive reconnection can be solved.