1. A theme changeable mouse for automatically matching network communities, comprising a substantial portion of a theme mouse 3 and a functional portion of auto-logging and matching communities 6 , wherein: the substantial portion of the theme mouse 3 comprises a mouse base 1 and a theme cover 2 which can be installed with a changeable model object 21 thereon; the mouse base 1 comprises a lower plate 11 , a printed circuit board 12 , a control circuit firmware 32 on the printed circuit board 12 , a page-rolling transmission gear wheel 13 , an annular seesaw key 14 , an outer annular page-rolling roller 15 , and a theme engaged cover 16 ; the theme cover 2 comprises the model object 21 having a crystal ball or a puppet of various styles and an engaged support plate 22 ; the model object 21 can be inserted into the engaged support plate 22 for mounting thereon; each of the model object 21 is provided with a sub-ID storage circuit 221 on a bottom thereof; the printed circuit board 12 of the mouse base 1 comprises a control circuit firmware 32 which is provided with a reading unit 321 and a recognition processing unit 322 therein for mutually executing a recognition interaction; the reading unit 321 is a detection and recognition module of electromagnetic induction or electric contact for reading out a sub-ID built in the theme cover 2 and transmitting it to the recognition processing unit 322 , so that the theme mouse 3 can provide more advanced information service, when the theme mouse 3 changes into various sub-IDs for automatically logging; and the functional portion of auto-logging and matching communities 6 comprises an information processing module 61 , an auto-registering/logging module 62 , and a database service and matching module 63 ; when the web server 7 receives a service request from a remote terminal computer host 5 , the information processing module 61 can decrypt obtained related information into a theme-ID which is then transmitted to the auto-registering/logging module 62 ; the auto-registering/logging module 62 can further determine if the theme-ID is a legal theme-ID, a new registering member, a cyberspace need of new theme content, or a general network auto-logging; corresponding procedures executed by the auto-registering/logging module 62 are further sent to the database service and matching module 63 for executing further corresponding procedures including opening a customized network service content and cyberspace of matched fans group, adding a new theme content and cyberspace, or responding a failure of logging cyberspace service, each of which is responded to the remote terminal computer host 5 , so as to automatically open the corresponding service or match for entering a specific community website.