The thermal degradable poly(alkoxyamine) was synthesized through a novel nitroxide radical coupling step growth polymerization (NRC-SGP) mechanism. The monomers of 1,4-phenylene bis(2-bromo-2-methylpropanoate) (monomer 1) and 1,4-phenylene bis(2-bromopropanoate) (monomer 1') with two bromide groups and 1,6-di(4-(2,2,6,6-tetramethylpiperidine-1-oxyl))-hexa-2,4-diyne (monomer 2) with two nitroxide radicals were first designed and synthesized. Then the NRC-SGP mechanism was investigated in detail by optimizing the factors such as polymerization time, temperature, solvents, catalysts, ligand, monomer concentration, and structures connected to halogen groups. The results showed that the termination by disproportionation was the major side reaction in the NRC-SGP mechanism, and the lower temperature (25 degrees C) would favor an important contribution. The proper combination of all factors could lead to an ideal NRC-SGP procedure. Finally, the thermal stability of formed poly(alkoxyamine) was monitored by TG, DSC and SEC instruments, and the results showed that the poly(alkoxyamine) would suffer a severe thermal degradation at the elevated temperature above 140 degrees C.