Five people were hospitalized with injuries, the Xinhua News Agency reported.
It was at least the sixth major bridge collapse in China since July of last year. The collapses have been blamed on shoddy construction and overloading, the report said.
The bridge ramp collapsed in Harbin city, capital of Heilongjiang province. In an unrelated incident in the same province, two passenger trains collided at a railway station Thursday, injuring at least 24 people.
The ramp, joining the Yangmingtan Bridge, tilted to one side and crashed to the ground about 5:30 am, the deputy head of the Harbin city construction committee said.
Photographs showed the crashed trucks turned upside down and the collapsed ramp resting almost perpendicular to the ground.
Xinhua said the 9.5-mile long, eight-lane bridge spanning the Songhua River and described as the longest bridge in north China was opened to traffic in November.