According to the requirements on site, we design a kind of portable maintenance assistant system equipment for airborne radar. Its system hardware platform adopts PXI structural system and possesses good compatibility and expansibility. This paper introduces design thought for this equipment (PMA) and expatiates its hardware structure; software system and functional design etc. during field support on some airborne radar site, this equipment (PMA) realizes fast extraction of radar data, quick diagnosis and isolation of failure, complete record for radar health state and the whole process control for field operation with fair reputation.