The causes and classification of organizational redundancy and the impact of organizational redundancy on investment efficiency were examined, and further research was conducted from the perspective of differences in ownership. Through empirical research, it is found that: (1) the more unabsorbed slack resources, the greater the possibility of overinvestment by the management; (2) there is no significant correlation between absorbed slack resources of enterprises and the possibility of overinvestment by the management; (3) compared with state-owned enterprises, non-stateowned enterprises have more unabsorbed slack resources, and the management is more likely to overinvest; (4) compared with non-stateowned enterprises, the more absorbed slack resources in state-owned enterprises, the greater the likelihood of management overinvestment.