According to my information,徐家庄露营地(Xujiazhuang Campsite) does have a contact number. You can reach them at:
+86-755-23118881 (in Chinese: 0755-23118881)
Please note that this phone number may be subject to change, and it’s always a good idea to double-check with other sources or visit their official website to confirm the accuracy of the contact information.