Modern astrophysics research has heavily relied on data measured from telescopes. Reasonable observational scheduling brings into play action on the output of highly sensitive data and utilization of telescopes. However, most existing observational scheduling methods aim to solve medium- to long-term problems with proposals as scheduled objects. Nevertheless, the Yunnan 40 m Radio Telescope (YRT40) has the requirements of short-term scheduling within a few days. In this paper, we present a time-dependent short-term observational scheduling method based on a genetic algorithm to achieve automatic scheduling of observation targets. We established a mathematical model of a multi-objective optimization with time dependence and the constraints of telescope hardware conditions with the aim of minimizing the slew time of the telescope and maximizing the scientific values of the targets. In the experiments, we adopted the actual observational targets of YRT40. The results from tests on the runtime of the telescope demonstrate the effectiveness of the proposed method.