这个句子是一个原因状语从句,可以翻译为因为他在国外厌倦了,所以他考虑回国
所以原句应为Because he is tired of being abroad,…
而在原因状语从句中,引导词和它后边的主语、be动词可以一并省略,所以就变成了Tired of being abroad,he is condering going back to china.
这句话也可以像你那样,理解为是完成时,但既然是主动,原句就应为Because he have tired of being abroad,…经省略后,还是一样的.