Power plane to be regarded AC GND?

During mulitilayer design, maybe regard the power plane to AC GND plane in order to design a stripline? Thks in advance.

In high frequency ,the power plane same as GND for stipline ,I think

sure.
You would see ac-grounded in any DC-Bias circuit for an AC analysis in SPICE simulator.

In my design,I would have splitted the whole power plane to two part: GND and POW.

Yes, technically a power plane can be regarded as an AC(RF) ground plane,
however I would personally not use a power plane as part of the
stripline ground.

This is because the device that is powered from the power plane may
introduce noise into the stripline. I therefore tend to keep 'real' ground
above and below any rf striplines and preferably add stitching ground
vias around the RF line.

Martin