Tremella polysaccharide (TP), one kind of green natural polysaccharide, exhibits different superior physical properties, which is a good choice to construct environmental‐friendly hydrogels. In the present study, TP hydrogels were designed with a "one‐step" approach, which via simply mixing TP solutions with different concentration of N,N‐methylenebis(acrylamide) (MBA) in NaOH/H2O solvent system. The experimental results showed that the NaOH concentration (1 %, 5 %, 10 %) and MBA concentration (6 mg/mL, 12 mg/mL and 18 mg/mL) had important influence on the gelation process of TP‐MBA hydrogels. When the concentrations of NaOH and MBA were 5 % and 18 mg/mL, respectively, the TP‐MBA hydrogel presented the shortest gelation time (2.5 h) and highest crosslinking density. Besides, the hydrogel formation mechanism was determined which suggested that the addition reaction between the −OH groups of tremella polysaccharide and the −C=C− bonds of MBA contributed to the formation of TP‐MBA hydrogels. In conclusion, this paper introduced a simple, efficient and green method for preparation of tremella polysaccharide‐based hydrogels. [ABSTRACT FROM AUTHOR]