Background: The issue of science is seldom brought into focus because of the way developing assessments of students' multiple text reading comprehension. Objectives: This study tested the sequential mediation model of scientific multi-text reading comprehension (SMTRC) by means of structural equation modelling (SEM), and aimed to advance the scientific multi-text reading comprehension assessment (SMTRCA), with a focus on discussing the causal relationship of potential variables in SMTRC. Method: Test items included 10 closed-ended and 7 open-ended questions and were categorised into four subscales: information retrieval (IR), information generalisation (IG), information interpretation (IIP), and information integration (IIG). Results: The confirmatory factor analysis results showed that there was an acceptable goodness-of-fit among the SMTRCA, indicating that the construct validity was good. Furthermore, the Cronbach's a of the test items was 0.88, indicating good internal consistency. In addition, using 1535 students, structural equation modelling was applied to analyse the relations of the latent variables. The findings showed that when readers are performing multitext reading comprehension, IR will simultaneously have direct influences on IG, IIP and IIG. Moreover, through IG, IR had an indirect impact on IIP; through IIP, IG had an indirect impact on IIG; through the two intermediate mediators of IG and IIP, IR had an indirect impact on IIG. Conclusion: In our data-driven model, multi-text reading comprehension is a hierarchical and complex cognitive process. That is to say, when an individual is engaging in multi-text reading comprehension, they will not just follow a single approach, but will deal with several cognitive processing routes simultaneously. Recommendations are made for future research to explore the cognitive model of scientific multi-text reading comprehension and to determine whether there are differences among multiple groups, as well as standard setting to define the cut-off scores of the criterion-referenced model, to develop an assessment reporting system of scientific multi-text reading comprehension, and strategies for scientific multi-text reading.