Statistical entropy of a cylindrical black hole

By using the method of quantum statistics, we directly derive the partition function of the bosonic and fermionic field in a cylindrical black hole. Then via the improved brick-wall method, the membrane model, we obtain that if we choose a proper parameter, the entropy of the black hole is proportional to the area of the. horizon. In our result, the stripped term and the divergent logarithmic term in the original brick-wall method no longer exist. In the whole process, we do not take any approximation. We offer a new simple and direct way of calculating the entropy of different complicated black holes.