The combined forces comprised personnel from the National Parks, Wildlife and Plant Conservation Department (DNP), the Royal Forest Department and the Fourth Regional Army.
The encroached park land is located in Muang district.
The operation was ordered by the National Council for Peace and Order (NCPO) as part of its efforts to safeguard the country's forests and natural resources.
Around 20 villagers witnessed the operation. None opposed it, or staked claims to the land or rubber trees.
Chaipat Boonphuphantanti, the chief of the park, said the operation would continue until Friday, with the aim of all encroachers being cleared from the park.
Mr Chaipat said the operation was launched after it was found villagers had been encroaching on the land and planting rubber trees since 1983.
Before the operation, Mr Chaipat ordered his subordinates to count the number of rubber trees planted on the encroached land. Of the 22,507 counted, most were felled yesterday.
The NCPO's crackdown on forest encroachment sees forest officials and soldiers working closely together, Mr Chaipat said.
Efforts are also underway to locate encroachers so authorities can pursue legal action against them, he said.
Over the last few years, five local people accused of encroaching on the national park have been brought to justice.
Two were given jail time, while the trial of the other three suspects is ongoing.
However, there are still many villagers guilty of encroaching on the national park that have so far escaped justice, Mr Chaipat said.
Samak Donnapee, director of the National Park Office under the DNP, said the department will continue to stamp out forest encroachment in national parks across the country.
Apart from taking legal action against forest encroachers and evicting them from the lands they occupy, the department plans to grow more trees and rehabilitate damaged forest land, Mr Samak said.
"People are concerned about environmental and natural resources issues. We have spent around 10 years trying to reclaim forest land from those using it for illegal activities.
"We hope this operation will enable us to reclaim the encroached forest soon so that we can return it to the people of Krabi," he said.
A source from the DNP said the locals that had encroached on the national park land to grow rubber trees were hired by a businessman living outside of Krabi province.
The source said officials would try and deal with the encroachment problem in a way that would limit conflict with villagers.
Under the NCPO-led encroachment crackdown, the DNP is expected to reclaim some 4,000 rai of forest land.
The operation in Krabi yesterday came after Monday's campaign in Phuket, where DNP officials and soldiers destroyed 18 food shops and stalls located along Nai Thon beach in Phuket province.