A simple, rapid response time and ultrahigh sensitive chemiluminescence (CL) DNA assay based on Fe3O4@SiO2@Au-functionalized magnetic nanoparticles (Au-MNPs) was developed for detection of p53 tumor suppressor gene. In this study, 2,6-dimethylcarbonylphenyl-10-sulfopropyl acridinium-9-carboxylate 4-NHS ester (NSP-DMAE-NHS), as a new kind of highly efficient luminescence reagent, was immobilized on the complementary sequence of the wild-type p53 (ssDNA) to improve the detection sensitivity. The optimal concentration of ssDNA-(NSP-DMAE-NHS) conjugates mixed with the wild-type p53 (wtp53) samples respectively. Then, the wtp53-Au-MNPs conjugates were added to continue the competitive reaction in the above solution. Subsequently, the Au-MNPs separated under magnetic field, measured by a homemade luminescent measurement system. Under optimal conditions, the method exhibited ultrasensitive sensitivity with a detection limit of 0.001ngmL(-1) (0.16pM), a wide range of liner response from 0.001ngmL(-1 similar to)6.6gmL(-1). Therefore, the immunomagnetic nanocomposites-based detection strategy was rapid, low-cost, and highly sensitive that can be easily extended to the early diagnosis of cancer development and monitoring of patient therapy.