It happened at about 7:42 a.m. in the southbound lanes just south of the Nojoqui Grade.
Video shows a truck losing control and spinning. CHP says that caused the driver of the car behind it to also lose control, drifting into the center median where it hit the front of a CHP car waiting to turn.
Unsafe speeds were said to be the cause of both vehicles losing control.
Minor injuries were reported.
The officer was stopped in the center median of Highway 101 just north of Highway 1, waiting to pull back into traffic after responding to two other collisions.