  For a gapped disordered many-body system with both internal and translation
symmetry, one can define the corresponding weak and strong Symmetry Protected
Topological (SPT) phases. A strong SPT phase is protected by the internal
symmetry $G$ only while a weak SPT phase, fabricated by alignment of strong SPT
state in a lower dimension, requires additional discrete translation symmetry
protection. In this paper, we construct a phase transition between weak and
strong SPT phase in strongly interacting boson system. The starting point of
our construction is the superconducting Dirac fermions with pair density
wave(PDW) order in $2d$. We first demonstrate that the nodal line of the PDW
contains a $1d$ boson SPT phase. We further show that melting the PDW stripe
and condensing the nodal line provoke the transition from weak to strong SPT
phase in $2d$. The phase transition theory contains an O(4)
non-linear-$\sigma$-model(NL$\sigma$M) with topological $\Theta$-term emerging
from the proliferation of domain walls bound to an SPT chain. Similar scheme
also applies to weak-strong SPT transition in other dimensions and predicts
possible phase transition from $2d$ to $3d$ topological order.
