  In this work, we systematically study the two-proton($2p$) radioactivity
half-lives using the two-potential approach while the nuclear potential is
obtained by using Skyrme-Hartree-Fock approach with the Skyrme effective
interaction of {SLy8}. For true $2p$ radioactivity($Q_{2p}$ $>$ 0 and $Q_p$ $<
$0, where the $Q_p$ and $Q_{2p}$ are the released energy of the one-proton and
two-proton radioactivity), the standard deviation between the experimental
half-lives and our theoretical calculations is {0.701}. In addition, we extend
this model to predict the half-lives of 15 possible $2p$ radioactivity
candidates with $Q_{2p}$ $>$ 0 taken from the evaluated atomic mass table
AME2016. The calculated results indicate that a clear linear relationship
between the logarithmic $2p$ radioactivity half-lives $\rm{log}_{10}T_{1/2}$
and coulomb parameters [ ($Z_{d}^{0.8}$+$l^{0.25}$)$Q_{2p}^{-1/2}$] considered
the effect of orbital angular momentum proposed by Liu $et$ $al$ [Chin. Phys. C
\textbf{45}, 024108 (2021)] is also existed. For comparison, the generalized
liquid drop model(GLDM), the effective liquid drop model(ELDM) and Gamow-like
model are also used. Our predicted results are consistent with the ones
obtained by the other models.
