In this article, we investigate the cooperative coverage detection problem of an unmanned ground vehicle (UGV) and an unmanned aerial vehicle (UAV) under visibility constraint. The control objective is to force the UGV and UAV to detect and cover a given area with the maximum effective coverage area and fast coverage speed. To this end, a hierarchical cooperative framework involving a maximum effective coverage (MEC) planning layer and a predefined-time tracking (PTT) control layer is proposed. In the MEC planning layer, the target path points of the UGV are deduced through geometric analysis, which is able to maximize the efficient coverage area, and then the desired trajectory of the UAV is derived according to the visibility constraint. In the PTT control layer, by combining two time-varying constraint functions and sliding mode theory, two predefined-time controllers are designed to drive the UGV and UAV to track their desired states obtained from the MEC planning layer within a predefined time, which means that the tracking time of the UGV and UAV can be set in advance just via a simple time parameter and thus is more convenient and faster than traditional methods. Finally, several simulations are provided to illustrate the effectiveness of the proposed approach.