Device-to-device (D2D) wireless ad hoc network architecture enables dynamic mobile userâ™s self- organizing communications which can directly exchange information between their peers without a pre-determined network infrastructure. Finite blocklength coding (FBC) has also been proved as the fifth generation (5G) promising candidate technique to support the time sensitive multimedia wireless networks services, where mobile users transmit short packets to upper- bound the transmission delay of video/audio traffics. The scaling law technique models the maximum D2D channel capacity as a function of the density of mobile users. Recent research works have integrated D2D wireless ad hoc networks with FBC theory to further improve the performances of 5G wireless ad hoc networks. However, how to model and analyze the capacity of D2D wireless ad hoc networks under the finite blocklength regime has not been well understood neither thoroughly studied. To overcome these challenges, applying the scaling law technique, we derive the upper-bound of the coding rate of each D2D channel and the number of time slots needed to complete all D2D transmissions. Combining the D2D channelâ™s coding rate with the number of time slots needed for all D2D transmissions, we derive the maximum aggregate throughput for wireless ad hoc networks with all mobile users using D2D communications while mitigating the interference. We also develop the model where each D2D channel follows the Nakagami-m distribution, under which we derive the average aggregate throughput and its upper- bound. Finally, we evaluate our derived results in the D2D wireless ad hoc networks over finite blocklength regime through numerical analyses.