How can I apply a Chinese visa if I travel by land fr Laos to china?

Im a M'Sian & holding S'pore PR. I will be flying to Bkk Then drive to northern Thailand city of Cheng Khong go to Laos side of Huaysai then drive north to the Chinese boarder of Mohan and drive to the city of Xishuangbanna for a tour in this city.