Rescue workers were called to the scene, at the entrance to Moo Baan Hua Nam, at about 10am after receiving a report that a bus had part of its roof ripped open in the collision.
Officers arrived to find the bus, registered in Nakhon Sri Thammarat, still in the middle of the road.
Bus driver Chairat Nonthakaew, 52, escaped with minor injuries, but two tourists, named as Wan Yibing and Ai Zijins, had already been taken to Thai Muang Hospital.
Police have yet to report the full extent of the tourists’ injuries.
The operator of the large digger, Khamthon Wang Khorglang 35, from Nakhon Ratchasima, was waiting at the scene when police arrived, confirmed Lt Col Jarun Srirat of the Thai Muang Police.
Police have yet to reveal any charges pressed for the collision.