How to judge whether there is an ancient tomb in a place? Is there any way or can we just wait until they are accidentally discovered?

There are methods, but the cost is so high. The accuracy is not very high. For example, aerial remote sensing, on the ground, there are resistivity method, magnetic exploration, electromagnetic exploration, ground penetrating radar, seismic exploration, mercury intrusion test, phosphate exploration and so on. Theoretically, all geophysical exploration methods can be applied in this respect. Of course, it is also helpful to look at Feng Shui and consult the literature.