The optical properties of self-assembled bilayer InAs/GaAs quantum dots (QDs) are investigated by photoluminescence (PL) and time-resolved photoluminescence (TRPL) as a function of the GaAs spacer thickness. First,the PL spectrum change with excitation intensity are investigated,the variation of PL intensity ratio between the seed layer of QDs (SQDs) and the top layer of QDs (TQDs) with respect to the excitation laser intensity reveals that the coupling and subsequently the interlayer carrier transfer between the two layers of QDs decreases with increasing the GaAs spacer thickness. Then, the temperature-dependent PL behaviors, in measurement of the peak energy (Emax), linewidth (Full Width of Half Maximum, FWHM), and the integrated intensity of QDs, show that the GaAs spacer thickness strongly affect the dynamics and the thermal quenching process of carrier in the bilayer QD structrures. At last,TRPL measurements show that the carrier tunneling time of the 60ML spacer QD sample is significantly longer than that of the 40ML spacer QD sample.