Europa,the second Galilean satellite outward from Jupiter,has an outer layer of water of about 100 km thick and an outmost ice shell. The thickness of the ice shell is very important in understanding Europa’s habitability and thermal history,but estimates from different studies are very inconsistent,ranging from 0.2 to 30 km. Here we obtain an estimate of the ice shell thickness from locations of flanking crack and forebulge along Ridge R. Considering the water’s heating process to nearby ice shell in the crack,a flexure model is applied and it suggests the thickness of an ice shell to be 500―1500 m without a convective layer. Compared with previous studies using the same method but ignoring the water’s heating process,the rationality and accuracy have been improved dramatically in our results. We also get some constraints on the strain rate ε and the characteristic temperature Tc,which defines the base of the elastic layer. Europa, the second Galilean satellite outward from Jupiter, has an outer layer of water of about 100 km thick and an outmost ice shell. The thickness of the ice shell is very important in understanding Europa’s habitability and thermal history, but estimates from different studies are very inconsistent, ranging from 0.2 to 30 km. Here we obtain an estimate of the ice shell thickness from locations of flanking crack and forebulge along Ridge R. Considering the water’s heating process to nearby ice shell in the crack, a flexure model is applied and Compared with previous studies using the same method but ignoring the water’s heating process, the rationality and accuracy have been improved dramatically in our results. We also get some constraints on the strain rate ε and the characteristic temperature Tc, which defines the base of the elastic layer.