Will the death of the King of Thailand affect the travel to Thailand?

Generally speaking, it has little impact. Except for the temporary closure of some scenic spots such as the Grand Palace and Jade Buddha Temple, everything else is open normally these days.

The National Tourism Administration of Thailand issued a statement saying that tourists are still welcome to visit during the national mourning period, but they should pay attention to dignified clothes, words and deeds and related etiquette. Tourists don't need black or white mourning clothes.