A double-stranded (ds) RNA virus composed of three dsRNAs was detected in the transcriptome of mulberry (Morus alba) collected from Ankang, Shaanxi Province, China, and named Mulberry cryptic virus 2 (MuCV2). The complete genome of this virus was assembled and confirmed using the RACE method. The dsRNA1 and dsRNA2 are 1,705 and 1,437 nt in length, and potentially encode an RNA-dependent RNA polymerase (RdRp) of 477 amino acids (aa) and a coat protein of 337 aa, respectively. The dsRNA3 is 1,357 nt in length, with an unknown functional open reading frame 3. The conserved sequence 5′-GAUAAUGAUY-3′ exists at the 5′-plus-strand termini of the three dsRNA segments of MuCV2. The RdRp shares over 70% identity with Arhar cryptic virus-I and Allium deltapartitivirus. The phylogenetic analysis of RdRp and CP sequences both provide support for MuCV2 being a new member of Deltapartitivirus (family Partitiviridae).