<p>Food security is vital for global health and sustainable development. However, existing validated versions of the Household Food Security Survey Module (HFSSM) cannot address the needs for a shorter Chinese version with a shorter reference period. This study aimed to examine the psychometric properties of a 6-item Chinese-version of the HFSSM (3-month reference period), among the economically deprived population in Hong Kong. This study included 512 observations from community-dwelling Chinese adults (≥ 18 years), who were social services users or food assistant service applicants, and with household income &lt; 75% of the population median. Construct validity and scale targeting were assessed using Rasch analysis. Convergent validity, known-group validity, internal consistency, and test-retest reliability were also examined. The construct validity was satisfactory, with a logical item calibration hierarchy and good infit statistics for five items (0.81–1.26), although a floor effect was indicated in the Wright map. The convergent validity was supported through a moderate positive correlation with the single-item household food insufficiency scale (<i>r</i> = 0.58). Known-group validity showed higher scores among those aged &lt; 65 years (d = 1.17,&#xa0;<i>p</i> &lt; 0.001), living with children aged &lt; 18 years (d = 1.09,&#xa0;<i>p</i> &lt; 0.001), enrolled in the food assistance program (d = 0.54,&#xa0;<i>p</i> &lt; 0.001), living at the poverty line or below (d = 0.30,&#xa0;<i>p</i> = 0.010), and with poor or fair health (d = 0.20,&#xa0;<i>p</i> = 0.028). Furthermore, the scale had fair-to-good internal consistency (Cronbach’s alpha = 0.88, Rasch person reliability = 0.64) and excellent test-retest reliability (ICC = 0.96) in one week. The 6-item Chinese-version of the HFSSM (3-month reference period) is a valid and reliable measure of household food insecurity in the economically deprived population in Hong Kong.</p>