With the rapid development of China’s S&T, public discourse is constantly reshaped by internet buzzwords which have become the digital carriers of social mentality and the emotion of the time. This research applied the internet buzzwords from 2000 to 2026 as its object, covering the different stages of Chinese internet era. Based on mainstream Chinese net-media, 20 representative internet buzzwords were collected annually, yielding 540 entries. After data screening of synonym merging, cross-year deduplication, and integration of etymologically related semantic items, 18 redundant duplicates were removed, resulting in a final analytical database comprising 522 valid internet buzzwords. Integrating the HowNet Emotional Dictionary, DUTIR and Chinese Emotional Lexicon, a five-tier emotional valence annotation system was constructed, categorizing the items into Strongly Negative (N1), Weakly Negative (N2), Neutral (N3), Weakly Positive (P4), and Strongly Positive (P5). In conjunction with linguistic features, specialized manual annotation rules were developed and conducted with stratified quantitative statistics of emotional distribution across the full sample. The results shew that the corpus comprehensively covered five major content domains varying from public expressions, social headlines, policy discourse, youth subculture, to industrial hotwords, and features long temporal coverage, all-scenario representation and stratified annotation. Weakly Positive buzzwords reached 247, accounting for the largest proportion and serving as the primary emotional carrier for daily entertainment and aesthetic expressions among netizens. Neutral items numbered 221, increasing year by year with the development of digital industries and AI technologies. Weakly Negative expressions came to 176, centrally carrying the life pressures and self-relieving emotions of the youth generation. Strongly Positive items, numbering 122, were concentrated in milestone years of major national projects, epochal policies, and national commemorative events, reflecting the spreading of mainstream discourse into cyberspace. Strongly Negative items lowered to only 40, heavily attached to malignant public events, with a significant decline after 2010. Temporal evolution patterns indicated that from 2000 to 2009, net buzzwords were predominantly driven by negative events; from 2010 to 2018, mild entertaining and positive words rose across the span; from 2019 to 2026, a diversified and balanced pattern emerged, featuring mainstream positive narratives, youth self-mockery and catharsis, and specialized digital terminology side by side. This research revealed the deep interlocking logic behind the emotional shifts in internet language over 27 years, involving media iteration, social governance, youth mentality, and national narratives, which drove Chinese cyberculture to disseminate with the balanced development of the closed-loop transmission path of national hardware and software.

Internet buzzword, emotional evolution, trend shift, five-tier emotional annotation system, cyberculture