Dynamic pushdown networks (DPN) consist of a group of dynamic pushdown systems (DPNS).And each DPNS model can dynamically demonstrate as new threads.Firstly

this paper introduces the real numeric clock to DPN to verify the real-time concurrent recursive system created by dynamic threads

and demonstrate it as time dynamic pushdown networks (TDPN).Secondly

this paper uses the clock equivalent optimization technique based on time key to convert a continuous TDPN models into a series of discrete TDPN models.Besides

this paper proposes the equivalence algorithm of TDPN into DPN.At last

we prove the status in TDPN is reachable if and only if its transition status in DPN is reachable.At the same time

this paper solves reachability problem of the real-time concurrent system created by dynamic threads.