I’m using the Bluemix Iot service and I have successfully make the device connect to both the bluemix and quickstart. Quickstart can achieve data visualization, but a web page can just display one device. Is the quickstart a kind of service which deploy in the Bluemix? if I want to design a webpage to show visualization of multiple devices, can I deploy any kind of service to achieve this function in Bluemix?
You could design a webpage to show visualization of multiple devices. To do this, you should create an IoT platform service and register your devices rather than using Quickstart.
See this visualization recipe for details. There is sample code available in GitHub.