Can I get a tourist visa to accompany my friend with work visa?

Yes, you can submit your application to Chinese embassy in Sri Lanka with documents from your friend, such as copy of his passport information page, copy of his residence permit/work visa, invitation letter. Beside, you need return air ticket, 3 months bank statement, hotel reservation details (if your friend invite you to live with him, the details should be written in the invitation letter with clear address), your travel itinerary (cities you plan to visit in China) are also needed. Visa officers are empowered to issue you visa according to documents you provide.